PROPERTY  OF 
J.   W.    DONAHUE 


MAS*. 


FOUNDATIONS 


AND 


FOUNDATION  WALLS, 

FOR  ALL  CLASSES  OF  BUILDINGS, 

PILE  DRIVING,  BUILDING  STONES  &  BRICKS, 

?IER  AND  WALL  CONSTRUCTION,  MORTARS,  LIMES,  CEMENTS,  CON^ 
CRETES,   STUCCOS,  ETC. 


64    ILLUSTRATIONS. 


PRACTICAL     EXPLANATIONS     OP    THE    VARIOUS    METHODS    OP     BUILDING    FOUNDATION 
WALLS  FOB  ALL   KINDS  OP  BUILDINGS.       TABLES  OP  THE  WEIGHT   OF  HATE- 
RIALS,    ETC.       THE   KIND    OF   MATERIALS    USED,    THE    LOADS    SUS- 
TAINED, AND   THE   SIZES  OF  WALL  PIEB8,  ETC.       USE  OF 
PILES    IN    FOUNDATIONS,    WITH    TERMS,     ETC. 
PLASTERING,  MORTARS,  LIMES  &  CEM- 
ENTS.     EXTRACTS    FROM    NEW 
YORK  BUILDING  LAWS, 
WITH    NOTES. 

By  GEORGE  T.  POWELL, 

A  rchitect  and  Civil  Engineer,  hew  York. 

TO  WHICH  IS  ADDED  A  TREATISE  ON   FOUNDATIONS,   WITH    PRACTICAL   ILLUSTRATIONS 
OF  THB  METHOD  OF  ISOLATED  PIERS,  AS   FOLLOWED  IN  CHICAGO, 

BY  FREDERICK  BAUMAN,  ARCHITECT. 


Revised  and  Enlarged  by  the  Addition  of  much  new  matter,  by 
G-.  T.  Powell. 


FOURTH  EDITION. 


NEW  YORK: 

WILLIAM  T.  COMSTOCK,  PUBLISHER, 

No.  23  WARREN  STREET. 

1889. 


WILLIAM  T.  COMSTOCK. 


PROPERTY  OF 
01  J.   W.   DONAHUE, 

SPfXNQfiPLD,    MAM. 


PUBLISHER'S  PREFACE. 


The  subject  of  Foundations  although  treated  of  in  various  works  on 
construction  has  not  heretofore,  with  the  exception  of  one  or  two  small 
manuals,  been  made  the  subject  of  a  special  book.  The  importance 
of  the  subject  and  the  liberal  patronage  afforded  the  first  edition  of 
this  work  had  led  the  publisher  to  believe  a  second  edition  thoroughly 
revised  and  brought  down  to  the  present  date  would  prove  valuable 
to  those  engaged  in  designing  and  constructing  large  and  important 
structures.  After  consultation  with  the  author  it  was  decided  to  re- 
cast the  whole  thing  and  make  it  practically  a  new  work.  With  this  in 
view  it  has  been  almost  entirely  rewritten  and  all  new  information  bear- 
ing on  the  subject  gathered  into  it. 

We  regret  to  say  that  the  author  after  completion  of  his  manuscript 
was  stricken  with  paralysis  and  in  consequence  unable  to  give  his  at- 
tention to  the  revision  of  proofs.  This  matter,  however,  has  been  very 
carefully  attended  to,  and  we  think  will  be  found  free  from  such  inac- 
C'uracies,  ambiguities  and  misprints  as  had  crept  into  the  first  edition. 
Since  the  first  edition  was  brought  out  there  have  been  many  import- 
ant structures  in  process  of  construction  where  the  subject  of  securing 
foundations  was  a  serious  study,  among  which  might  be  named,  the 
Brooklyn  Bridge.  The  tests  made  for  these  structures  and  other  knowl- 
«dge  gained  regarding  use  of  cements  etc.,  have  been  carefully  garner- 
ed and  will  be  found  under  their  proper  headings  in  the  following 
pages. 

On  the  preservation  of  timber  the  author  is  largely  indebted  to  the 
researches  of  Maj.  Gen.  Cram  of  the  U.  S.  A.,  and  has  quoted  largely 
from  his  lecture  before  the  Franklin  Institute  in  Philadelphia. 

In  order  to  cover  the  subject  more  fully  than  has  been  done  hereto- 
fore the  author  has  found  it  necessary  to  increase  the  number  of  illus- 
trations and  very  much  increase  the  amount  of  letter  press. 

The  practical  experience  of  the  author  and  his  careful  collection  of 
the  materials  of  information  on  this  subject  leads  us  to  feel  that  this 
book  will  prove  to  be  a  valuable  aid  to  Architects,  Builders  and  Engi- 
neers in  solving  the  many  difficult  problems  arising  where  important 
structures  have  to  be  erected  on  treacherous  soils.  Trusting  that  the 
same  generous  patronage  will  be  accorded  to  it  as  heretofore  we  now 
offer  it  to  the  building  and  engineering  fraternities. 


CONTENTS. 


CHAPTER  I. 

Foundation  walls  on  soil  or  stratum  not  liable  to  be  affected  by 

weather,  air  or  water.— Clay 9 — 13 

CHAPTEK  H. 

Foundations  in  soft  ground  of  considerable  depth. — Boring  to  test 
bottom.  —  Timber  pile  foundations.  —  Foundations  in  quick- 
sand. —  Foundations  in  shifting  sand.  —  Structures  built  on 
slopes. — Pile  driving. — Terms  used  in  pile  driving. — Size  and 
kind  of  wood  for  piles. — To  find  safe  load  for  pile  to  carry. — 
Height  of  ram  to  fall.— Set  of  pile  at  last  blow.— Weight  of 
rams. — Experiments  in  Brooklyn  Navy  Yard.— Protection  of 
piles. — Decay  and  preservation  of  timber. — Worms  in  wood  on 
land  and  in  open  air. — Worms  in  wood  under  sea-water 13—32 


CHAPTER  HI. 

Excavations. — Rule  to  be  complied  with. — Footings  and  footing 

courses. — Chimneys. — Trenches  for  footings. — Springs  in  cellars.    33—41 

CHAPTER  IV. 

Stone  foundations. — Walls.— Brick  for  footings. — Use  of  stone  for 
building  purposes. — Strength  of  building  stone. — Footing  stones. 
— Inverted  arches. — Table  of  weight  of  timbers. — Weight  of 
building  stones 42 — 68 

CHAFfER  V. 

Arches  in  walls. — Construction  of  arches. — Chimney  walls  and  build- 
ing the  same. — Proportion  of  brick  chimneys.— Masons'  and 
stone-cutters'  tools. — Stone-cutting. — Rubble  footings. — Bond 
rubble.  —  Random  coursed  stone  work. — Regular  faced  and 
squared  stone  work. — Trimmed  and  coursed  Ashlar  facing. — 
List  of  stones  for  the  exterior  of  buildings. — Dry  area  of  brick 


71  CONTENTS. 

or  rubble.— Prevention  of  dampness  in  cellar  walls.— Sylvester's 
process  of  repelling  moisture  from  external  walls. — Damp. — 
Hollow  brick  walls.— Floors  in  damp  locations.— Air  and  water- 
tight cements  for  casks  and  cisterns. — Cement  for  external  use. — 
Cement  to  resist  red  heat  and  boiling  water.— Cement  to  join 
sections  of  cast-iron  wheels.— Soft  cement  for  steam  boilers.— 
Gas-fitters'  cement. — Plumbers'  cement. — Coppersmiths'  cem- 
ent.—Composition  to  fill  holes  in  castings.— Cast-iron  cement. — 
Cement  for  Aquaria > 59 — 76 


CHAPTER  VI. 

Front  vaults. — Retaining  walls.— Slopes.— Table  of  strength  of  stone 
for  vaults,  galleries,  etc. — Table  of  experiments  on  brick. — 
Table  for  calculating  weight  of  materials  in  building. — Law  in 
reference  to  load  on  floors.— Mensuration  of  superfices.— Hollow 
walls  for  buildings. — Building  Laws  passed  Apr.,  1871. — Preser- 
vation of  stone.— Incrustations  on  brick  walls.— Sulphuret  of 
lime.— Sand 77—97 


CHAPTER  VH. 

Preparation  of  common  mortar. — Gravel  sidewalks.— To  color  bricks 
black. — Staining  bricks  red  or  black. — Venetian  cement.  Coal- 
ash  mortar. — Puzzolana  mortar.— Dutch  Terras  mortar.— Plas- 
tering or  stucco. — Inside  plastering. — Two-coat  work  and  fin- 
ish. Stone  mortar.— Stucco.  — Scratch  coat.— Slipped  coat. — 
Cement  for  external  use. — Asphalt  composition.— Asphalt  mas- 
tic.— Asphalt  for  walks. — Cement  for  fronts  of  houses. — Cement 
for  tile  roofs.— Cement  for  outside  brick  walls.— Mexican  meth- 
od for  making  hard  lime  floors.— Selenitic  mortar  or  cement. — 
Selenitic  clay. — Mixing  selenitic  mortar  and  concrete. — Propor- 
tion of  sand  to  lime. — Concrete  construction. — Ancient  cem- 
ents.—Rapidity  of  set.— Color.-r-Packiiig  the  cement.— Water 
for  mixing.— Sand-gravel  etc.,  for  mixing  with  Portland  cement. 
— Proportion  of  cement  in  mortar  and  concrete. — Mixing  and 
laying  Portland  cement  concrete. — Fineness. — Expanding  or 
contracting  in  setting. — Strength.— Tests  of  cement. — Hydraulic 
limes  and  cements. — Salt-water  mortars. — Mortars  exposed  to 
air.— Betons  and  concrete.  —  Portland  cement.— French  beton 
agglomere.— Vicat  cement.— Lafarge  cement.— Table  of  Amer- 
ican and  Foreign  cements. — Keene's  cement. — Polished  work 
of  walls.— Stucco  on  brick-work.— Rosendale  cement  concrete. 
— Portland  cement  concrete.— Selenitic  lime  or  cement.— Cem- 
ent mortar  for  brick  laying.— Mortar  of  cement.— Cement  mor- 
tar for  stone  masonry.— Cement  mortar  for  brick  masonry. — 
Ordinary  concrete.— Brick-dust  and  cement  concrete.— Lime  and 
cement  concrete.— Table  of  tests  of  hydraulic  and  other  cements 


CONTENTS.  VII 

at  Centennial  Exhibition. — Collingwood  on  cements. — Roman 
cement.— Vicat's  hydraulic  cement. — Stone  cement.  —  Glue. — 
Cement  mortar.— Concrete. — Test  of  Portland  cement. — Street 
pavements.  —  Macadamized  roadways.  —  Artificial  stone  pave- 
ments for  sidewalks. — Belgian  pavement. — Guidet  pavement. — 
Sidewalks. — Method  of  calculating  load  on  floors 98-146 


ART  OF  PREPARING  FOUNDATIONS 

BY 
FREDERICK   BAUMAN,    (ARCHITECT.) 

FIRST  PART. 

<Lc  of  treating  the  ground. — Solid  grounds. — Compressible  grounds. 
— Building-ground  of  Chicago. —  Method  of  isolated  piers. — 
Concrete.— Semi-fluid  grounds 146-163 

SECOND  PART. 

The  Base. — Dimension  stone. — Rubble  stone. — Concrete. — Mortar. 

of  chimneys 163-16C 


THE  PROPERTY  OF 

SPRINGFIELD,  BASS, 


FOUNDATIONS  AND  FOUNDATION  WALLS. 


CHAPTER  I. 

Foundations. 

The  term  Foundation  is  used  to  signify  the  bed  or  bottom 
of  earth,  gravel  or  rock  which  must  be  prepared  to  receive  the 
base  consisting  of  footings  and  foundation  walls.  The  object 
to  be  attained  in  the  construction  of  all  foundation  walls  is  to 
form  solid  footings  of  proper  proportion  to  the  superstructure. 

Foundations  may  be  divided  into  two  great  classes. 

First. — Foundations  in  situations  where  the  natural  soil  is 
sufficiently  firm  to  bear  the  weight  of  the  intended  structure. 

Second. — Foundations  in  situations  where  artificial  supports 
must  be  provided  in  consequence  of  the  softness  or  looseness 
of  the  soil.  Each  of  these  classes  may  be  subdivided  into  many 
kinds  under  the  heading  of  Engineering  works  but  it  is  the  in- 
tention to  confine  this  book  more  particularly  to  the  founda- 
tions of  buildings. 

Foundation  Walls  on  Soil  or  Stratum  not  liable  to  be  affected 
by  Weather,  Air  or  Water. — In  building  on  a  natural  bottom  of 
this  kind,  it  is  necessary  to  level  the  surface  or  footing  space, 
so  that  the  walls  or  piers  may  start  from  a  horizontal  bed.  If 
irregularities  occur  in  the  firm  ground,  it  will  be  best  to  fill  them 
up  with  concrete,  rather  than  to  use  stone  or  brickwork.  Where 
some  portions  of  the  foundations  start  below  the  level  of  the 
others,  care  must  be  taken  to  keep  the  mortar  or  cement  joints 
as  close  as  possible,  or  to  execute  the  lower  portion  of  the  work 
in  cement  or  hard-setting  lime  mortar. 

Strong  gravel  may  be  considered  as  one  of  the  best  soils  to 
build  upon,  as  it  is  not  affected  by  exposure  to  the  atmosphere, 
and  is  almost  incompressible  and  easily  leveled. 


10 


POWELL  S    FOUNDATIONS 


While  sand  resists  compression  and  makes  a  firm  foundation, 
it  must  be  kept  from  shifting,  or  being  acted  upon  by  water. 

In  many  cases  it  is  necessary  to  drive  sheath  or  board  piles 
and  use  cement. 

Rock  or  partly  solid  rock  bottom  requires  good  judgment 
and  careful  handling;  for  it  commonly  happens,  in  the 
area  of  a  large  building,  that  some  portions  will  rest  on 
rock  and  others  upon  clay  or  loose  gravel,  and  these  differences 
in  the  character  of  the  soil,  are  liable  to  produce  irregularities 
in  settlement,  and  are  often  difficult  to  make  firm  enough  to 
carry  the  load  of  masonry  uniformly.  A  common  rule,  when 
possible,  is  to  reduce  the  rock  to  a  certain  level,  sufficiently 
deep  for  the  footings,  and  then  remove  the  soft  soil,  and  make 
a  bed  of  say  three  feet  of  concrete,  bringing  the  concrete  to  the 
level  of  the  stone ;  all  of  which  is  explained  by  the  following 
practical  illustrations. 

To  prepare  the  surface  of  stone  bottoms  of  irregular  or  in- 
clined strata,  it  is  necessary  to  reduce  the  stone  or  brick  to 
level  surfaces,  thus — (ill.  i  and  2.) 


ILLUSTRATIONS  i  AND  2. 

or  quarry,  excavate,  and  carry  the  whole  to  a  common  level. 

Beds  of  Rock  with  clay  are  not  very  safe  without  artificial 
treatment,  especially  if  there  are  partings  or  strata  of  clay,  and 
if  they  lay  in  inclined  positions.  In  ill.  3,  for  instance,  when 


AND   FOUNDATION   WALLS. 


ir 


ILLUSTRATION  3. 

turning  arches,  the  springing  line  or  base  of  arch  on  one  side 
might  be  secure,  while  the  opposite  side  would  be  liable  to- 
move  from  the  pressure  of  the  load  on  the  arch ;  this  may  be 
made  secure  by  drilling,  and  driving  iron  bars  into  holes  pass- 
ing through  the  strata. 

Clay. — The  most  deceptive  kind  of  ground  to  build  upon  is 
clay.  Its  inseatrity  results  from  the  position  of  its  strata,  as 
well  as  its  elasticity,  from  being  mixed  with  marl,  etc.,  and  its 
tendency  to  absorb  moisture.  In  dry  seasons  it  is  very  firm, 
while  in  wet  seasons  it  is  elastic  and  unreliable.  It  is  known 
that  whole  buildings  have  been  injured  by  the  moving  of  clay 
strata.  Of  course  this  insecurity  is  not  likely  to  occur  on  level 
strata  or  firm  clay. 

But  when  the  layers  of  clay  are  inclined,  too  much  care  can- 
not be  observed,  especially  where  the  distribution  of  the  load  is 
quite  uneven,  as  for  instance  in  structures  where  piers,  towers, 
or  chimneys  occur  along  with  solid  walls.  It  is  always  well  to 
disconnect  towers. 

When  dry  clay  rammed  around  foundation  walls  becomes  wet, 
it  has  a  tendency  to  bulge  them. 

All  buildings  settle  a  little,  if  from  no  other  cause  than  the 
weight  of  the  walls  and  floors. 

Shifting  clay  bottoms  that  are  very  insecure  have  been  built 
upon  by  laying  round  timbers,  one  foot  apart,  on  concrete  ;  the 


12  POWELL'S  FOUNDATIONS 

space  between  the  timbers  being  laid  with  concrete,  and  filled 
to  the  top  of  the  logs,  to  receive  stone-slab  footings.  This 
method  will  do  on  structures  of  about  thirty  feet  in  height,  and 
inexpensive  buildings. 

The  best  soils  for  foundation  walls  are :  gravel  and  close 
pressed,  hard,  sandy  earth  that  will  resist  the  pick — or  rock  bot« 
torn  where  a  horizontal  base  may  be  made. 

If  there  is  reason  to  believe  that  the  earth  below  is  yielding 
it  is  best  in  ordinary  cases  to  dig  rough  wells  and  fill  them  with 
stone  to  the  footings  in  the  cellar  bottom ;  dig  say  6  feet  be- 
low cellar  bottom.  These  wells  may  be  arranged  to  support 
walls  of  40  to  145  feet  in  height. 


AND   FOUNDATION   WALLS.  IJ 


CHAPTER  II. 

To  Secure  Solid  Foundations  in  Soft  Ground  of  considerable 
depth. 

In  cases  of  this  kind  where  the  expense  of  building  from  a 
great  depth  to  the  surface  is  too  great,  a  number  of  supports  or 
columns  can  be  brought  up  through  the  soft  ground,  on  which 
to  set  wall  plates  of  wood,  stone  or  iron  for  footing  courses. 
There  are  a  variety  of  ways  in  which  this  may  be  done. 

First :  By  excavating  holes  through  the  soft  ground,  and  fill- 
ing with  sand ;  this  is  done  by  boring,  or  driving  down  a  wooden 
pile,  then  withdrawing  it  and  filling  the  hole  with  sand.  This 
method  is  not  often  used  in  this  country,  although  if  an  ample 
number  of  holes  are  filled  with  sand  well  packed,  a  secure 
foundation  may  be  obtained. 

Second. — By  driving  piles  of  wood  either  by  hand  or  with 
the  ordinary  steam  engine  ;  the  piles  to  be  driven  until  they 
are  firm  and  secure  in  the  solid  earth,  and  kept  from  any  side 
movement  by  bracing  with  horizontal  timber. 

Third. — By  screwing  piles  into  the  soft  ground  for  a  bearing. 
The  screw  fixtures  attached  to  piles  are  expensive  and  are  not 
generally  used  on  city  buildings. 

The  cast  or  wrought  cylinder  screw  piles  are  usually  from 
3  to  8  in.  diameter  and  have  at  the  foot  a  cast  screw  with  a 
blade  from  18  in.  to  5  ft.  diameter;  they  are  generally  used  on 
docks  and  railroad  work  and  are  screwed  into  clay,  marl  or  sand  by 
using  capstan  bars.  On  engineering  works  where  many  of 
these  piles  are  sunk  a  special  machine  is  used  for  the  purpose, 
generally  worked  by  steam.  This  system  of  piling  is  too  ex- 
pensive for  buildings  and  is  seldom  used  except  on  dock  work. 

Certain  kinds  of  soft  soil  have  a  tendency  to  stir  into  a  mud 
batter  upon  driving  piles  into  them.  In  this  case  drive  with 
hand  power  a  few  guide  piles  and  then  build  square  or  parallel 
cribs  of  timber  and  fill  the  space  with  stone  closely  packed,  also 


1 6  POWELL'S  FOUNDATIONS 

work  of  horizontal  timber.  In  timber  piling  the  load  is  trans- 
mitted only  in  the  direction  of  its  length.  There  are  also  many 
cases  where  stone  footings  are  used  and  laid  directly  on  the  top 
of  the  piles ;  but  too  much  care  cannot  be  taken  in  a  case  like 
this  to  obtain  security. 

Illustration  4  shows  an  elevation  of  framing  on  top  of  piles. 
'This  is  the  plan  adopted  in  the  construction  of  a  factory  built 
'on  the  marshes  near  Hoboken,  New  Jersey.  The  building  is 
50  by  100  feet,  and  about  20  feet  in  height.  The  piles,  of  yel- 
low pine,  were  thirty  feet  in  length,  and  from  nine  to  twelve 
inches  diameter.  After  being  driven,  they  were  cut  to  a  level 
of  two  feet  below  water-line,  and  spaced  for  the  outside  walls 
four  feet  to  centers.  On  top  of  these  were  placed  sills.  12x12 
inches;  on  top  of  the  sills  were  framed  uprights,  12x12,  four 
feet  long,  braced  from  all  sides  ;  on  top  of  uprights  was  placed 
a  second  sill,  that  received  a  twelve-inch  wall.  The  piles  for 
wooden  pillars  through  center  are  eight  feet  to  centers.  The 
piles  for  the  chimney  and  engine-room  are  about  twenty  inches 
apart,  with  timbers  crossing  each  other,  forming  a  foundation  for 
stone  slabs,  on  top  of  which  is  built  the  brickwork.  The  foun- 
dation of  timber  is  cross-braced  from  center  to  outside ;  and 
notwithstanding  the  motion  of  the  machinery,  no  unequal  set- 
tling has  occurred,  although  it  may  have  settled  one  inch  be- 
fore becoming  fixed  and  solid. 

Foundations  in  Quicksand. — 

It  is  not  uncommon  to  find  quicksand  in  New  York  City. 
In  many  localities  large  masses  of  sand  surcharged  with  water 
until  it  becomes  quick  are  found  at  a  depth  of  from  5  to  20  ft. 
In  nearly  all  cases  there  is  a  mixture  of  leaden  colored  silt  or 
soapstone  slime.  This  is  a  kind  of  marl  nearly  white  when  it 
is  dry,  but  when  mixed  with  the  sand  holds  a  large  amount  of 
water.  It  is  often  the  case  in  excavating  through  quick-sand 
that  strata  of  this  blue  marl  occurs ;  it  is  tough  and  hard  to 
move  but  it  is  utterly  unfit  for  Foundations  of  any  kind.  An- 
other difficulty  often  occurs  when  layers  of  cemented  clay  and 
gravel  are  found.  It  is  slow  to  dig  with  shovels  or  picks,  and 
can  only  be  taken  out  in  small  quantities,  adding  greatly  to  the 
expense.  In  nearly  all  cases  where  quicksand  is  found  it  will 
be  necessary  to  provide  hand  or  steam  pumps  with  leaders  or 


AND   FOUNDATION    WALLS.  \"J 

gutters,  to  remove  the  water.  It  is  useless  to  attempt  the  re- 
moval of  the  sand  and  ooze  until  the  water  is  drawn  off  and 
where  any  natural  drainage  can  be  obtained,  channels  should  be 
made  in  every  direction  possible.  It  is  often  necessary  in  this 
kind  of  soil  to  provide  temporary  platforms  and  roadways, 
while  making  the  excavation,  as  the  disturbance  of  the  soil  con- 
sequent upon  prosecution  of  the  work  is  liable  to  make  a  slough. 
Where  there  are  large  masses  of  quicksand  which  are  imprac- 
ticable to  remove,  owing  to  locality  or  surroundings,  drive  piles, 
not  disturbing  the  soil  more  than  is  necessary,  and  secure  them 
to  horizontal  timbers,  forming  cribs,  then  brace  the  whole  and 
fill  the  interstices  with  concrete  made  of  broken  stone,  sand 
and  lime. 

One  way  to  proceed  to  secure  footing  in  this  soil  is  to  drive 
sheath  piles  on  the  outside  and  inside  line,  leaving  the  space 
between  to  be  excavated.  Brace  the  sheath  piles  adding  sec- 
tion after  section,  as  the  excavation  proceeds.  Have  prepared 
concrete  enough  to  fill  in  each  section,  proceeding  in  this  way 
until  the  work  is  completed. 

Where  the  soil  offers  no  resistance  to  sheath  pile  or  brace, 
construct  long  wooden  cases  with  sides  and  bottoms  (Caissons) 
made  of  2  or  3  in.  boards  securely  bolted  and  framed  together. 
Set  these  in  sections  and  in  the  position  where  they  are  to  be 
lowered  ;  they  are  then  to  be  loaded  to  the  top  with  rough  con- 
crete and  sunk  with  their  own  weight  to  the  depth  required. 
Tests  may  be  made  by  loading  these  cases  with  iron  to  the 
average  weight,  per  sq.  ft.,  expected  to  be  borne.  The  combi- 
nation of  quick  sand,  marl,  hard-pan,  etc.,  found  in  excavations 
is  often  carelessly  passed  by  and  ordinary  broad  footing  stones 
used,  resulting  in  many  cases  in  unequal  settling  and  the  ruin 
of  fine  buildings.  Broad  footings  of  stone  are  allowable  where 
the  soil  is  not  too  soft,  but  two  or  three  courses  should  be  laid 
with  a  batter  of  half  their  thickness. 
\ 

To  build  Foundations  on  shifting  sand. 

In  speaking  of  this  subject  it  will  be  well  to  state,  that  the 
place,  condition  of  sand  and  the  opportunity  to  secure  the  bot- 
tom of  the  structure  will  vary  so  much  that  these  directions 
will  hardly  apply  to  every  case.  Excavate  an  open  space  in  the 


16  POWELL'S  FOUNDATIONS 

work  of  horizontal  timber.  In  timber  piling  the  load  is  trans- 
mitted only  in  the  direction  of  its  length.  There  are  also  many 
cases  where  stone  footings  are  used  and  laid  directly  on  the  top 
of  the  piles ;  but  too  much  care  cannot  be  taken  in  a  case  like 
this  to  obtain  security. 

Illustration  4  shows  an  elevation  of  framing  on  top  of  piles. 
'.This  is  the  plan  adopted  in  the  construction  of  a  factory  built 
on  the  marshes  near  Hoboken,  New  Jersey.  The  building  is 
50  by  100  feet,  and  about  20  feet  in  height.  The  piles,  of  yel- 
low pine,  were  thirty  feet  in  length,  and  from  nine  to  twelve 
inches  diameter.  After  being  driven,  they  were  cut  to  a  level 
of  two  feet  below  water-line,  and  spaced  for  the  outside  walls 
four  feet  to  centers.  On  top  of  these  were  placed  sills.  12x12 
inches;  on  top  of  the  sills  were  framed  uprights,  12x12,  four 
feet  long,  braced  from  all  sides  ;  on  top  of  uprights  was  placed 
a  second  sill,  that  received  a  twelve-inch  wall.  The  piles  for 
wooden  pillars  through  center  are  eight  feet  to  centers.  The 
piles  for  the  chimney  and  engine-room  are  about  twenty  inches 
apart,  with  timbers  crossing  each  other,  forming  a  foundation  for 
stone  slabs,  on  top  of  which  is  built  the  brickwork.  The  foun- 
dation of  timber  is  cross-braced  from  center  to  outside ;  and 
notwithstanding  the  motion  of  the  machinery,  no  unequal  set- 
tling has  occurred,  although  it  may  have  settled  one  inch  be- 
fore becoming  fixed  and  solid. 

Foundations  in  Quicksand. — 

It  is  not  uncommon  to  find  quicksand  in  New  York  City. 
In  many  localities  large  masses  of  sand  surcharged  with  water 
until  it  becomes  quick  are  found  at  a  depth  of  from  5  to  20  ft. 
In  nearly  all  cases  there  is  a  mixture  of  leaden  colored  silt  or 
soapstone  slime.  This  is  a  kind  of  marl  nearly  white  when  it 
is  dry,  but  when  mixed  with  the  sand  holds  a  large  amount  of 
water.  It  is  often  the  case  in  excavating  through  quick-sand 
that  strata  of  this  blue  marl  occurs ;  it  is  tough  and  hard  to 
move  but  it  is  utterly  unfit  for  Foundations  of  any  kind.  An- 
other difficulty  often  occurs  when  layers  of  cemented  clay  and 
gravel  are  found.  It  is  slow  to  dig  with  shovels  or  picks,  and 
can  only  be  taken  out  in  small  quantities,  adding  greatly  to  the 
expense.  In  nearly  all  cases  where  quicksand  is  found  it  will 
be  necessary  to  provide  hand  or  steam  pumps  with  leaders  or 


AND   FOUNDATION    WALLS.  If 

gutters,  to  remove  the  water.  It  is  useless  to  attempt  the  re- 
moval of  the  sand  and  ooze  until  the  water  is  drawn  off  and 
where  any  natural  drainage  can  be  obtained,  channels  should  be 
made  in  every  direction  possible.  It  is  often  necessary  in  this 
kind  of  soil  to  provide  temporary  platforms  and  roadways, 
while  making  the  excavation,  as  the  disturbance  of  the  soil  con- 
sequent upon  prosecution  of  the  work  is  liable  to  make  a  slough. 
Where  there  are  large  masses  of  quicksand  which  are  imprac- 
ticable to  remove,  owing  to  locality  or  surroundings,  drive  piles, 
not  disturbing  the  soil  more  than  is  necessary,  and  secure  them 
to  horizontal  timbers,  forming  cribs,  then  brace  the  whole  and 
fill  the  interstices  with  concrete  made  of  broken  stone,  sand 
and  lime. 

One  way  to  proceed  to  secure  footing  in  this  soil  is  to  drive 
sheath  piles  on  the  outside  and  inside  line,  leaving  the  space 
between  to  be  excavated.  Brace  the  sheath  piles  adding  sec- 
tion after  section,  as  the  excavation  proceeds.  Have  prepared 
concrete  enough  to  fill  in  each  section,  proceeding  in  this  way 
until  the  work  is  completed. 

Where  the  soil  offers  no  resistance  to  sheath  pile  or  brace, 
construct  long  wooden  cases  with  sides  and  bottoms  (Caissons) 
made  of  2  or  3  in.  boards  securely  bolted  and  framed  together. 
Set  these  in  sections  and  in  the  position  where  they  are  to  be 
lowered  ;  they  are  then  to  be  loaded  to  the  top  with  rough  con- 
crete and  sunk  with  their  own  weight  to  the  depth  required. 
Tests  may  be  made  by  loading  these  cases  with  iron  to  the 
average  weight,  per  sq.  ft.,  expected  to  be  borne.  The  combi- 
nation of  quick  sand,  marl,  hard-pan,  etc.,  found  in  excavations 
is  often  carelessly  passed  by  and  ordinary  broad  footing  stones 
used,  resulting  in  many  cases  in  unequal  settling  and  the  ruin 
of  fine  buildings.  Broad  footings  of  stone  are  allowable  where 
the  soil  is  not  too  soft,  but  two  or  three  courses  should  be  laid 
with  a  batter  of  half  their  thickness. 
* 

To  build  Foundations  on  shifting  sand. 

In  speaking  of  this  subject  it  will  be  well  to  state,  that  the 
place,  condition  of  sand  and  the  opportunity  to  secure  the  bot- 
tom of  the  structure  will  vary  so  much  that  these  directions 
will  hardly  apply  to  every  case.  Excavate  an  open  space  in  the 


i8 


POWELL  S    FOUNDATIONS 


sand  larger  than  the  base  of  the  structure,  lay  timber  footings, 
parallel  with  the  line  of  the  walls,  cross  them  with  timbers  un- 
til a  solid  platform  is  prepared  and  pin  them  together  with  oak 
or  metal  pins.  Then  make  a  diagonal  cover  of  say  i  3-4  in. 
rough  boarding,  either  nailed  or  pinned  ;  on  this  platform  or 
deck  run  sill  plates  to  the  siz.e  of  the  frame  required  and  se- 
cure them  to  the  timber  footings,  and  on  these  sill-plates  set  the 
corner  posts  and  put  in  braces  ;  then  erect  the  frame  construc- 
tion as  may  be  necessary  for  the  purpose.  This  platform  or 
deck  will  require  inclosing  sides,  thus  making  a  large  box  to  re- 
ceive the  sand.  The  load  of  sand  will  balance  and  hold  in  po- 
sition the  whole  structure.  It  is  estimated  that  each  cubic  ft. 
of  space  in  a  frame  structure  will  average  1 5  Ibs.  and  each  cubic 
ft.  of  sand  105  Ibs.  or  seven  times  heavier  than  the  frame  ;  now 
if  the  frame  is  35.  feet  high  the  box  must  be  loaded  with  sand 
5  feet  deep.  As  an  additional  security  long  horizontal  timbers 
with  timber  anchors  may  be  extended  from  the  bottom  of  the 
box.  It  is  important  to  load  the  bottom  of  the  structure  and 
place  it  below  the  wash  of  the  water.  The  weight  of  the  sand 
alone  need  not  equal  the  weight  of  the  structure  provided  it  is 
heavy  enough  to  secure  the  foundations  from  shifting. 


ILLUSTRATION  5. 


AND    FOUNDATION    WALLS.  IQ 

Illustration  5  represents  the  foundations  of  a  factory  building 
erected  near  the  edge  of  the  water  line  in  the  marshes  of  Long 
Island.  The  soil  is  a  stiff  black  muck.  Trenches  were  cut 
through  this  four  feet  wide,  and  averaged  six  feet  deep  to  a  par- 
tial quicksand  bed.  The  building  is  50  by  80  feet ;  two  stories, 
1 6  feet  each;  with  four  feet  of  brickwork,  above  ground,  to 
level  of  first  floor.  The  walls  above  are  sixteen  inches  thick. 
After  the  trenches  were  dug,  a  bedding  of  ten  inches  in  thick- 
ness of  concrete  was  laid.  On  top  of  this  two  inches  spruce 
plank  are  laid  crosswise,. followed  with  8x8-inch  timber,  laid 
parallel  with  the  trenches,  and  the  spaces  filled  in  with  con- 
crete. On  this  are  laid  the  base  stones,  on  top  of  which  is 
built  a  twenty-inch  brick-wall.  The  trenches  on  each  side  of 
wall  were  filled  up  with  sand. 

This  factory  has  an  engine,  boiler,  machinery  and  shafting, 
with  an  hundred  operatives.  No  settling  has  occurred. 

Structures  built  on  slopes  are  always  liable  to  slide.  In  prac- 
tice this  is  avoided  by  cutting  horizontal  steps  in  the  slope,  but 
great  care  should  be  used  in  erecting  the  walls  to  thoroughly 
bond  the  stone  at  all  stepping  places.  Such  work  should  pro- 
ceed slowly  so  as  to  avoid  unequal  settling  as  the  greater  quan- 
tity of  mortar  in  the  wall  on  the  lower  portions  of  the  slope 
will  cause  much  greater  settling  there  than  in  the  walls  on  the 
upper  part  of  the  slope  and  a  consequent  breaking  of  joints  at 
the  stepping  places.  The  foundations  should  be  leveled  in  as 
long  sections  as  possible  and  the  footings  carefully  laid,  especial- 
ly at  the  stepping  places. 

Pile  Driving — The  usual  method  of  driving  piles  is  by  a  suc- 
cession of  blows  given  by  a  heavy  block  of  wood  or  iron,  called 
a  ram,  monkey  or  hammer,  which  is  raised  by  a  rope  or  chain, 
passed  over  a  pulley  fixed  at  the  top  of  an  upright  frame,  and  al- 
lowed to  fall  freely  on  the  head  of  the  pile  to  be  driven.  The 
construction  of  a  pile-driving  machine  is  very  simple.  The  guide 
frame  is  about  the  same  in  all  of  them  :  the  important  parts  are 
the  two  upright  timbers,  which  guide  the  ram  in  its  descent. 
The  base  of  the  framing  is  generally  planked  over  and  loaded 
with  stone,  iron,  or  ballast  of  some  kind,  to  balance  the  weight 
of  the  ram.  The  ram  is  usually  of  cast-iron,  with  projecting 


2O 


POWELL'S  FOUNDATIONS 


tongue  to  fit  in  the  grooves  of  frame.  Contractors  have  all  sizes 
of  frames,  and  of  different  construction,  to  use  with  hand  or 
steam  power,  from  ten  feet  to  sixty  feet  in  height.  The  height 
most  in  use  is  one  of  twenty  feet,  with  about  twelve  hundred 
pound  ram.  In  some  places  the  old  hand-power  method  has  to 
be  used  to  avoid  the  danger  of  producing  settling  in  adjoining 
buildings  from  jarring. 

Piles  should  be  driven  to  sink  not  more  than  one  inch  to  the 
last  blow  of  the  hammer.  The  hammer  used  should  be  equal 
in  weight  to  the  pile.  The  common  size  of  piles  is  ten  to  four- 
teen inches  in  diameter,  and  they  are  driven  with  hammers  or 
rams  weighing  twelve  hundred  to  two  thousand  pounds  each. 
The  diameter  of  the  pile  should  be  about  one-twentieth  of  the 
length. 

The  present  way  of  driving  piles  with  steam  power  is  very  ob- 
jectionable where  permanent  structures  are  to  be  built,  as  the 
severe  and  frequent  jarring  is  liable  to  work  the  soil  into  a  soft 
mass. 


ILLUSTRATION  6. — Piles,  &c.,  showing  Water  Line. 

Terms  used  ill  Pile  Driving. — A  Pneumatic  Pile  is  a  metal 
cylinder  and  is  driven  by  atmospheric  pressure,  the  air  being 
exhausted  from  within. 

A  Hollow  Pile  is  a  cylinder  which  is  sunk  by  excavation  pro- 
ceeding inside. 

A  Screw  Pile  has  an  augur  at  the  lower  end,  and  is  sunk  by 
rotation,  aided  by  pressure. 

A  Close  Pile  is  one  of  whole  timber,  set  close  to  the  others. 

A  False  Pile  is  an  additional  length  added  to  a  pile  after 
driving. 


AXD    FOUNDATION   WALLS.  2! 

A  Filling  Pile  is  to  fill  the  space  between  gauge  piles. 

A  Foundation  Pile  is  one  for  supporting  a  structure. 

A  Gauge  Pile  is  a  preliminary  pile  to  mark  the  desired  course. 

A  Guide  Pile  limits  the  field  of  operation. 

A  Sheet  Pile  is  of  half  timbers  in  contact,  filling  the  gaps  be- 
tween gauge  piles. 

A  Wale  is  a  horizontal  string-piece  to  bind  the  piles. 

Pile  Hoop,  a  band  around  the  top  to  prevent  splitting. 

Pile  Shoe,  the  metallic  point. 

Test  Pile,  the  first  pile  driven  to  test  the  bottom  and  should 
be  not  less  than  six  inches  in  diameter. 

Size  and  Kind  of  Wood  for  Piles. — Piles  are  generally  round, 
and  from  nine  to  eighteen  inches  at  top,  and  should  be  straight 
and  clear  of  bark  and  projecting  limbs,  etc.  But  where  piles 
are  exposed  to  the  rising  and  falling  of  tides,  for  wharves,  tres- 
tle-work, etc.,  they  are  considered  to  be  the  best  if  driven  with 
the  bark  on.  Trees  are  sometimes  selected  for  this  purpose ; 
and  when  the  foliage  is  full,  just  on  the  change,  the  tree  is  gir- 
dled— that  is,  the  bark  near  the  bottom  is  separated  by  cutting 
it  off  sufficient  to  kill  the  tree,  and  two  or  three  months  later 
the  trees  are  felled.  This  method  shrinks  the  bark  close  to  the 
wood. 

White  pine,  spruce,  or  even  hemlock  answer  very  well  in  soft 
soils.  Florida  yellow  pine  makes  the  best  for  general  use  but  oak, 
elm  and  beech  for  the  more  compact  soils.  Piles  are  generally 
spaced  from  two  to  four  feet  to  centres.  Squared  piles  and  ta- 
pering ones  will  not  bear  equal  loads.  All  should  be  as  near 
uniform  in  size  as  possible. 

All  timber,  driven  into  the  earth,  having  the  common  name 
of  piles,  may  be  divided  by  calling  those  that  stand  on  solid  foun- 
dations Posts,  and  those  that  depend  on  the  friction  of  the  earth 
and  its  constituents  Piles,  these  last  require  to  be  considered 
very  carefully  for  their  sustaining  power.  Although  piles  may 
resist  the  hammer  it  is  sometimes  difficult  to  tell  whether  the 
resistance  is  from  having  reached  a  firm  strata  or  is  only  caused 
by  friction.  In  such  cases  always  allow  a  large  proportion  for 
safety,  and  bind  the  piles  together,  or  brace  them.  In  nearly 
all  calculations  that  are  made  for  pile  driving,  the  calculations 


22  POWELLS     FOUNDATIONS 

are  based  on  the  soil  being  homogeneous,  that  is,  assuming  the 
soil  to  be  the  same  kind  all  the  way  down.  Now  this  seldom 
occurs,  as  there  may  be  alluvium,  clay,  gravel,  marl,  shale  or 
pebbles,  and  some  variety  occurs  in  nearly  all  localities.  As  it 
is  difficult  to  find  a  locality  to  suit  the  formula,  it  is  best  to  ac- 
cept the  judgment  of  experienced  builders,  who  are  experts  in 
this  specialty. 

The  force  in  pounds  with  which  a  pile  hammer  makes  its  blows 
upon  the  head  of  the  pile  is  very  indefinite,  as  all  the  rules  differ 
very  much.  Correct  data  may  be  gathered  from  actual  tests,  as 
follows  :  In  the  fine  stone  London  Bridge  crossing  the  Thames 
each  pile  sustains  eighty  tons.  They  are  driven  only  twenty 
feet  in  the  stiff  blue  London  clay,  and  are  four  feet  to  centres,, 
and  are  twelve  inches  diameter  in  the  middle.  This  proved  too 
much  of  a  load.  At  about  three  feet  on  centres  they  would  have 
had  only  forty-five  tons  to  sustain.  Traxitwine  states  that  at  the 
Chestnut  Street  bridge,  Philadelphia,  the  greatest  weight  on  any 
pile  is  eighteen  tons.  Mr.  Kneas  had  the  piles  driven  until  they 
sank  three-quarters  (.75)  of  an  inch,  under  each  blow,  from  a 
i2oo-pound  hammer,  falling  twenty  feet.  Here  we  have  the  fall 
in  inches:  20  x  12  =  240  inches,  divided  by. 75  =  320  x  1200 
Ibs.  =  384.000  Ibs.,  divided  by  8,  =  48.000  Ibs.,  or  21  1-4  tons 
safe  load  ;  but  it  is  best  in  practice  to  use  only  one-half  of  the 
estimated  safe  load. 

The  refusal  of  a  pile  intended  to  support  a  weight  of  thirteen 
and  a  half  tons,  can  be  safely  taken  at  ten  blows  of  a  ram  of  1350 
pounds,  falling  twelve  feet,  and  depressing  the  pile  eight-tenths 
of  an  inch  at  each  stroke. 

Some  engineers  consider  a  pile  safe  for  a  load  of  twenty-five 
tons  when  it  is  driven  to  the  refusal  of  1350  pounds,  falling  four 
feet,  not  to  sink  more  than  four-tenths  of  one  foot  under  thirty 
blows.  On  mud  and  marsh  bottoms  it  is  best  not  to  load  the 
piles  more  than  one-quarter  of  the  above  amount. 

The  following  are  a  number  of  rules  for  calculations  in  refer- 
ence to  the  strength  and  bearing  capacity  of  piles. 

To  find  the  Safe  Load  which  the  Pile  is  to  Carry.— Given  : 

The  weight  of  ram,  the  height  the  ram  falls  in  inches,  and  the 
set  of  pile  at  last  blow,  in  inches. 


AND    FOUNDATION    WALLS.  2J 

Rtde — Multiply  the  weight  of  ram  by  the  height  it  falls,  and 
divide  the  product  by  eight  times  the  set  of  pile  at  last  blow. 

To  find  the  Height  for  the  Ram  to  Fall  in  Inches.— Given  : 

The  set  of  pile  at  last  blow  in  inches,  the  safe  load  which  the 
pile  is  to  carry  in  cwts.  (of  112  pounds),  and  the  weight  of  ram. 
Rule — Multiply  the  safe  load  which  the  pile  is  to  carry  by 
eight  times  the  set  of  pile  at  last  blow,  and  divide  the  result  by 
the  weight  of  ram. 

To  find  the  Set  of  Pile  at  last  Blow.— Given  :  Weight  of  ram, 
height  the  ram  has  to  fall  in  feet  and  the  safe  load  the  pile  is  re- 
quired to  hold  in  cwts.  (of  112  pounds.) 

R^lle — Multiply  the  weight  of  the  ram  by  the  height  it  falls, 
and  divide  the  product  by  eight  times  the  safe  load  which  the 
pile  is  to  carry. 

To  find  the  Weight  of  Kams  in  cwts.  (of  112  pounds.)— 

Given  :  The  set  of  pile  at  last  blow  in  inches,  the  height  the 
ram  is  to  fall  in  inches,  and  the  safe  load  the  pile  is  to  carry  in 
cwts.  (of  1 12  pounds.) 

Rule — Multiply  the  safe  load  the  pile  is  to  carry  by  eight 
times  the  set  at  last  blow,  and  divide  the  product  by  the  height 
the  ram  falls. 

Pile  drivers  who  are  experts  know  when  their  piles  strike  rocks, 
and  sometimes  band  the  tops  to  prevent  them  from  swaying. 

The  following  are  the  results  of  experiments  on  piles  at  Fort 
Montgomery  :  The  piles  were  twelve  to  sixteen  inches  in  diame- 
ter, and  nine  to  fourteen  inches  at  the  smallest  end,  and  were 
from  twenty-nine  to  thirty-three  feet  long  after  cutting ;  They 
were  of  spruce,  and  weighed  about  forty  pounds  per  cubic  foot, 
and  were  driven  with  a  ram  or  hammer  of  1630  pounds,  at  a 
height  of  thirty-five  feet.  The  last  blows  made  them  sink  from 
two  and  a  half  to  six  inches.  Compressibility  of  soil  about 
one-eighth  of  its  entire  bulk. 

Experiments  at  the  Brooklyn  Navy  Yard. — The  piles  were 
twelve  to  eighteen  inches  at  top,  and  seven  inches  at  foot ; 
length  of  piles  after  cutting  averaged  thirty-two  feet ;  weight  of 
ram,  2240  pounds,  and  height  of  fall  twenty-five  feet.  Average 
number  of  blows,  seventy-three.  They  were  driven  into  fine 
sand,  uniform  in  quality. 


24  POWELLS    FOUNDATIONS 

In  starting  all  work  of  pile  driving,  a  test  pile,  of  six  or 
eight  inches  diameter,  should  be  driven  to  test  the  bottom,  and 
of  about  the  same  length  that  it  is  the  intention  to  drive  the 
Foundation  Pile. 

A  number  of  piles  driven  for  piers,  and  a  cast-iron  cylinder 
sunk  around  them,  and  secured  at  the  top,  the  earth  removed 
from  the  inside,  and  the  cylinder  filled  with  concrete,  makes  an 
excellent  foundation. 

Where  timber  foundations  have  to  be  constructed,  and  the 
posts  or  piles  of  wood  are  exposed  to  the  rising  and  falling  of 
tides  and  sea-water,  they  are  liable  to  the  attacks  of  wood-boring 
worms  that  will  destroy  ordinary  timber  in  three  to  five  years. 
One  of  these  is  the  Limnoria  Terebrans,  and  is  about  three 
sixteenths  of  an  inch  long.  These  little  creatures,  assisted  by 
the  action  of  the  sea,  will  soon  cut  a  pile  through,  as  the  sur- 
face rots  rapidly  after  being  perforated  by  them.  The  other  is 
the  Teredo  Navalis,  and  is  also  known  as  the  ship-worm.  It 
will  penetrate  the  wood  from  fifteen  to  twenty-five  feet  below 
mean  low  tide.  It  is  found  in  most  countries.  It  grows  to 
about  three  inches  long,  and  one-quarter  inch  diameter,  and  has 
a  head  like  an  auger,  with  the  point  gone.  They  leave  very 
small  holes  where  they  have  entered,  which  would  not  attract 
attention,  while  inside  the  wood  is  completely  honey-combed. 
Their  attacks  are  generally  confined  to  timber  above  low  water 
mark.  Mr.  C.  G.  Smith,  C.  E.,  mentions  the  ship-worm,  and 
gives  some  particulars  about  the  kind  of  wood  that  will  remain 
sound  longest  in  sea-water. 

TABLE. 

Beach  (with  Payne's  patent  process)  ....  10  years,  7  months,  first  decay. 

Teak  Wood  (East  India) 5  years,  6  months,  first  decay. 

English  Oak  (Kyanized)  ....  5  years,  good ;  10  years,  0  months,  unsound. 

British  Ash 3  years,  good ;    5  years,  0  months,  unsound. 

American  Oak 3  years,  good ;    5  years,  0  months,  unsound. 

Pitch  Pine 3  years,  good ;    5  years,  0  months,  unsound. 

Yellow  Pine 3  years,  good;    4  years,     slightly  unsound. 

It  appears  that  they  do  not  so  frequently  attack  bark,  as  it 
kills  them  before  they  penetrate.  If  the  outside  could  be  shrunk 
with  heat,  slightly  charred,  and  coated  with  carbolic  paint,  mixed 
with  Trinidad  asphalt,  it  is  thought  this  would  give  great  pro- 


AND    FOUNDATION    WALLS. 


tection.  Copper  lining  has  sometimes  been  resorted  to,  but 
this  is  too  expensive  for  general  use.  There  is  an  English  Sili- 
cate Paint  used,  not  readily  affected  by  water ;  and  when  there 
is  a  covering  on  the  silicate  of  asphalt  of  tar  and  oil,  it  tends  to 
repel  their  attacks. 


ILLUSTRATION  7. — Wrought  or  Cast-iron  Shoes  to  Piles. 

Another  method  :  All  that  portion  of  the  pile  exposed  to  the 
action  of  sea  or  fresh  water,  should  have  a  coat  of  crude  carbol- 
ic paint.  When  this  has  dried,  put  on  a  coat  of  asphalt  hot,  and 
wrap  coarse  canvas  or  bagging  fabrics  spirally  around  the  pile, 
saturated  with  hot  asphalt ;  and  when  this  has  set,  finish  with 
another  coat  of  asphalt  hot.  After  this  it  is  ready  to  drive. 
Piles  treated  this  way  are  not  attacked. 

Before  closing  this  chapter,  I  will  state  that  "it  is  important 
that  every  foundation,  for  either  large  or  small  structures,  should 
be  prepared  to  sustain  the  load  of  the  walls,  the  materials  of  the 
building,  and  the  load  to  be  sustained  on  each  floor."  The  re- 
sult of  these,  added  together,  gives  the  load  to  be  sustained 
(with  an  average  of  thirty  pounds  per  square  foot  on  roof  for 
snow).  And  the  foundations  should  be  made  so  firm  that  no  doubt 
will  arise  about  their  being  insecure. 

In  connection  with  Driving  Piles. — It  is  often  found  neces- 
sary to  protect  the  work  above  ;  and  paint  the  iron  fastenings. 
Several  kinds  of  paint  are  used,  lead  paint  is  generally  too  expen- 
sive, and  hence  the  use  of  Bituminous  Paints.  A  paint  made 
from  bitumen,  dissolved  in  parrafine  and  linseed  oil  when  very 
hot,  has  special  qualities  of  durability,  and  will  resist  alkalies 
and  acids. — A  tar  varnish  composed  as  follows  is  very  good  :  30 


26  POWELL'S  FOUNDATIONS 

gallons  fresh  coal  tar,  6  Ibs.  tallow,  i  1-2  Ibs.  rosin,  3  Ibs.  lamp 
black,  and  30  Ibs.  freshly  slacked  lime  ;  mix  and  apply  hot :  When 
dry,  this  varnish  will  receive  on  its  surface  any  color  of  oil  paint. 

Decay  and  Preservation  of  Timber,  from  a  Lecture  delivered 
at  the  Franklin  Institute  in  Philadelphia,  Penn.,  by  Maj.  Gen'L 
Cram,  U.  S. 

Decay  and  Preservation  of  Timber — I  have  known  oak  and 
pine  beams,  encased  in  solid  brick  masonry  where  hardly  any 
air  or  moisture  could  reach,  perfectly  rotten  after  eleven  years 
of  such  imprisonment. 

Nor  can  it  be  maintained  that  all  kinds  of  untreated  wood  ex- 
posed to  soil,  air  and  water  will  very  speedily  decay.  The 
speediness  of  decay  of  timber  thus  exposed  will  depend 
upon  the  kind  of  wood,  the  particular  acids  or  salts  in 
the  soil,  the  climate  where  the  timber  is  to  be  used,  and  the 
thickness  of  the  sticks.  To  illustrate  this,  it  is  only  necessary 
to  adduce  a  few  facts  which  have  come  under  my  own  observa- 
tion, also  some  well  authenticated  circumstances  coming  under 
the  observation  of  other  engineers  of  constructions. 

In  houses  of  the  old  dilapidated  town  of  Chagres,  lignumvitae 
mudsills  were  found,  after  lying  seventy-two  years  upon  the 
ground,  perfectly  sound.  This  induced  the  engineers  of  the 
Panama  R.  R.  Co.,  to  replace  their  first  ties,  which  were  of  the 
very  best  Georgia  pine,  and  which  lasted  not  to  exceed  three- 
years,  with  lignumvitae  brought  from  Darien,  at  a  cost  (in  1855) 
of  $  i.oo  per  tie.  The  same  Georgia  pine  taken  to  a  northern 
climate  would  have  lasted  as  railroad  ties  seven  years,  at  least, 
before  requiring  renewal. 

Red  cedar  heart  in  its  natural  state  as  fence  posts  and  mud- 
sills has  lasted  fifty  years  in  the  clay  and  gravelly  loam  in  nor- 
thern climates  without  appreciable  decay,  but  in  strong  lime  soil 
it  yields  in  less  time  ;  while  white  or  yellow  cedar  will  last  only 
from  fifteen  to  twenty  years  before  it  will  become  decayed  in  a 
similar  exposure  and  soil. 

In  the  rich  bottom  lands  of  Wisconsin,  I  saw  the  original 
massive  white  oak  trunks  exhumed  as  it  were  from  beneath  the 
mucky  ground,  where  they  had  been  upturned  by  an  ancient 


AND    FOUNDATION    WALLS.  2f 

tornado,  and  timber  made  from  them  in  1842  ;  the  wood  was  then 
perfectly  sound  after  an  age  of  centuries,  and  the  timber  made 
from  them,  used  in  a  construction  under  cover,  is  at  the  present 
time  as  sound  as  ever. 

The  untreated  "redwood"  of  California,  in  contact  with  soil 
from  volcanic  debris,  I  found,  on  testing  its  durability,  quite  as 
lasting  as  our  red  cedar,  though  it  is  by  no  means  the  same  kind 
of  wood.  It  is  weak  and  brittle  ;  neither  is  it  the  same  kind  of 
wood  as  the  "mammoth  trees"  of  that  State. 

I  have  found  our  northern  red  cedar,  treated  with  the  old  Ky- 
an  process,  an  infusion  of  corrosive  sublimate,  after  twenty-two' 
years'  exposure  lying  on  a  slope  of  strong  limy  soil,  to  have  gone 
to  decay,  especially  the  lower  ends  of  the  sticks,  and  kyanized 
white  oak  of  Michigan,  resting  upon  the  same  kind  of  dirt,  dozed 
and  rotted  twenty  years  after  the  treatment. 

Chestnut  railroad  ties  grown  upon  the  barrens  of  Maryland, 
kyanized  and  laid  upon  a  limy  soil  some  miles  north  of  Baltimore 
in  1838,  I  saw  tested  eleven  years  afterwards  and  then  perfectly 
sound,  and  more  solid  than  when  laid  ;  while  those  of  the  same 
kind  of  wood,  untreated,  but  laid  at  the  same  time  in  the  same 
kind  of  soil  and  exposure  with  the  treated  ones,  lasted  only  sev- 
en years  before  they  required  renewal. 

This  experiment  of  kyanizing  timber  was  the  first,  I  believe, 
ever  practiced  in  our  country.  Ties  enough  were  treated  for 
one  mile  of  track,  costing  twelve  and  a  half  cents  per  cubic  foot 
of  timber.  The  process,  however,  was  so  unhealthy,  salivating 
all  the  men,  it  had  to  be  abandoned.  It  would  be  worth  while 
to  ascertain  if  those  kyanized  ties  are  yet  sound.  At  that  time 
the  untreated  ties  cost  only  fourteen  to  sixteen  cents. 

The  original  growth  of  white  soft  pine  of  New  England,  in 
fence  boards  untreated  and  not  touching  the  ground,  has  been 
known,  after  an  exposure  of  more  than  fifty  years,  to  be  free  from 
all  signs  of  decay,  while  heavy  sticks  of  timber  of  the  same  wood 
and  similar  exposure  were  found  much  decayed  in  a  shorter 
period.  White  spruce  and  red  hemlock  of  that  part  of  our  coun- 
try I  found,  on  examination,  untreated,  would  only  last,  the  for- 
mer eleven  years,  and  the  latter  nineyears^  while  white  hemlock 
is  more  durable  than  either. 

Untreated  white  oak  and  white  elm  piles,  which  must  have 


28  POWELL'S  FOUNDATIONS 

been  driven  at  least  forty  years,  I  have  found  perfectly  sound 
all  below  and  for  one  or  two  feet  above  water,  their  tops  being 
injured  only  by  abrasion.  In  these  waters  there  is  no  need 
of  treating  by  any  antiseptic  the  timbers  to  be  placed  under 
water. 

But  for  all  the  horizontal-side,  end  and  tie  timbers  above  the. 
first  foot  above  water,  the  experience  is  quite  different.  As  a 
general  rule,  I  have  found  these  timbers  to  show  decay  in  seven 
years  after  being  laid  without  treatment ;  and  yet  many  have 
lain  from  twelve  to  fifteen  years ;  but  then  they  have  become  so 
rotten  as  to  be  blown  away  by  the  winds  or  torn  off  by  the  waves. 
Without  treatment,  therefore,  by  some  antiseptic  we  cannot  re- 
ly upon  the  timber  in  these  superstructures  lasting  more  than 
•seven  years  without  need  of  renewal. 

In  the  pier  superstructures,  we  have  used  chiefly  white  and 
hard  or  red  pine  and  white  oak.  The  vast  amount  of  beautifully 
shaped  timber  for  the  sizes  we  need,  but  deemed  as  too  inferior 
in  quality  for  these  superstructures,  growing,  however,  in 
the  vicinity  of  the  lake  shores,  such  as  hemlock,  white  cedar, 
bass,  fir,  white  and  black  ash,  hickory,  white  elm,  beech,  syca- 
more, etc.,  etc.,  are  utterly  ignored.  An  antiseptic  that  would 
materially,  say  double  or  triple  the  period  of  decay  in  these 
would  enable  us  to  bring  them  into  use,  at  a  cost  for  the  un- 
treated timber  considerably  below  that  of  pine  and  oak. 

The  ancient  Egyptians  must  have  known  of  antiseptics  for 
preserving  wood.  Their  old  wooden  coffins,  after  2,000  years, 
have  been  brought  to  light ;  and  a  gentleman  of  much  experience 
in  the  causes  of  decay  and  means  of  "preservation  of  wood,"  has 
informed  me,  he  "has  seen  several  of  these  split  to  pieces,  and 
that  the  wood  (sycamore)  was  perfectly  sound  and  strong ;  the 
wood  seemed  to  have  been  impregnated  with  a  bituminous  sub- 
stance. The  coffins  were  'dug  outs'  from  solid  blocks  of  the 
wood,  leaving  a  hole  in  the  top  to  insert  the  corpse,  and  having 
a  lid  carved  and  ingeniously  fitted  to  enclose  the  aperture." 
Now  sycamore,  as  we  know  it,  untreated,  is  not  a  very  lasting 
wood.  Whether  the  lost  art  is  to  be  recovered  by  the  use  of 
modern  antiseptics  remains  to  be  seen  by  future  generations. 

Worms  in  Wood  on  Land  and  in  the  Open  Air, — There  is  a 
destructive  attack  by  these  upon  wood  of  the  trees  which  have 


AND    FOUNDATION    WALLS.  2£ 

been  cut  into  logs,  out  of  which  timber  and  lumber  are  to  be 
manufactured  at  the  mill. 

The  trees  are  generally  felled,  and  immediately  cut  into  lengths 
suitable  for  these  logs,  in  the  winter,  and  either  hauled  to  the 
mill  during  the  same  winter  or  rafted  to  it  early  in  the  spring 
and  sawed  during  the  same  spring  and  succeeding  summer.  In 
this  way  the  eating  by  the  worm  is  in  a  great  measure  avoided. 
But  if  the  logs  of  almost  any  kind  of  wood  are  allowed  to  lie  over 
the  summer  on  the  ground,  they  almost  invariably  become  eaten 
unless  they  are  "drossed,"  which  means,  to  hew  off  their  bark. 
Peeling  the  bark  of  the  hemlock  in  June  for  tanneries,  will  pre- 
vent the  worm  in  this  kind  of  wood. 

If  the  season,  however,  is  very  wet  and  cold,  logs  with  their 
bark  on  are  less  liable  to  attack  where  they  lie  over  ;  and  if  they 
are  "boomed,"  or  put  into  a  "log  bay"  of  fresh  water,  they  are 
preserved  from  this  kind  of  worm,  unless  the  eggs  of  the  larva 
are  laid  in  the  logs  before  they  can  be  put  into  the  water,  in 
which  case  the  larva  are  known  to  develop  into  the  living  worm 
in  six  months  after  sawing  and  sticking  up  the  stuff,  which,  though 
apparently  free  from  the  worm  when  piled,  soon  becomes  great- 
ly injured,  as  many  a  pile  of  supposed  valuable  timber  has  shown. 

When  a  thrifty  tree,  however,  is  overturned  by  the  roots  and, 
after  dying,  cut  into  saw-logs  or  hewn,  no  worms  will  be  found 
in  the  wood. 

Some  of  the  very  best  lumber  comes  from  wind-falls  after  the 
trees  have  been  dead  for  years,  taking  care,  however,  not  to 
sever  the  rooty  mass  from  the  trunks  while  green.  These  facts 
led  to  the  explanation  of  the  manner  in  which  these  worms  are 
produced  in  saw-logs  and  green  timber  recently  felled  by  the  axe. 
A  small  insect  easily  penetrates  by  the  ends  of  the  green  log 
along  through  its  whole  length  in  the  palatable  juices  between 
the  dark  and  sap  wood  and  deposits  her  eggs,  which  very  rapidly 
develop  into  eating  worms.  No  doubt  there  are  various  kinds 
and  sizes  of  these  preying  upon  wood,  and  among  which  may  be 
classed  the  ants,  which  are  so  destructive  to  wood  in  tropical 
climates. 

A  wind-fall,  with  its  up-turned  roots  having  earth  attached, 
affords  no  access  to  the  insect ;  and  when  the  green  logs  are 
"drossed,"  there  is  no  bark  shelter  for  the  insect  which  dreads 


3O  POWELL  S    FOUNDATIONS 

the  water  so  much  that  it  will  not  enter  the  logs  after  an  immer- 
sion in  fresh  water. 

It  seems  to  me  that  if  the  lumber  manufacturer  has  the  ill 
luck  of  being  compelled  to  allow  the  green  logs  to  lie  over  on 
the  ground,  the  besmearing  of  the  ends  with  some  cheap  bad 
smelling  paint  might  prevent  the  access  of  the  insect. 

Worms  in  Wood  tinder  Sea-water.  —  These,  I  have  observed, 
on  our  sea-coasts,  seldom  work  upon  piles  and  dock-facing  tim- 
bers, except  in  those  parts  standing  between  half  ebb  and  half 
flood  tides ;  in  the  space  between  these  two  planes,  however, 
their  operations  are  indeed  wonderful  and  dreadfully  destructive. 
On  some  of  the  European  coasts,  I  think  they  range  in  their  at- 
tacks from  extreme  low  to  nearly  high  tide. 

It  is  not  very  many  years  since  it  was  believed  these  worms 
could  only  exist  in  the  tropical  climates,  and  that  they  were  only 
known  in  cold  climates  by  being  brought  in  vessel  bottoms.  But 
this  was  an  illusion  which  experience  has  since  dispelled. 

As  far  east  as  Castine  Harbor,  Me.,  they  began  destroying 
piles  and  other  dock  timbers  of  the  best  white  oak,  and  so  ef- 
fectually did  their  work  that  renewals  had  to  be  made.  It  is 
believed  they  were  introduced  there  from  old  worm-eaten  ves- 
sels coming  home  and  lying  to  the  docks  until  the  vessels  no 
longer  afforded  substance  for  boring,  then  the  worms  forsook, 
and  resorted  to  the  piles  and  dock  timbers.  No  oak  has  for  years 
been  used  there  for  the  renewals.  Yellow  pine  is  used,  and  as 
long  as  the  resin  remains  in  the  wood,  it  is  comparatively  free 
from  the  worm  ;  but  after  a  few  years,  the  resin  becomes  washed 
out,  then  the  worms  commence  the  havoc  in  good  earnest. 

In  various  places  on  our  Atlantic  coast  from  Maine  to  Mexico, 
and  on  our  own  Pacific  coast,  this  annoying  and  costly  evil  ex- 
ists. There,  I  have  observed,  no  vessel  or  wood  structure,  ex- 
cept as  high  up  as  about  where  the  fresh  water  and  the  tide 
water  meet,  is  safe  from  this  evil.  The  remedy  of  covering  the 
exposed  parts  with  the  sheet  copper  is  only  effectual  until  the 
sheathing  becomes  punctured,  torn,  or  abraded  off,  then  the 
worms  immediately  enter. 

In  the  bay  of  San  Francisco,  the  worms  are  very  active  and 
produce  great  havoc.  They  bore  deep  into  the  piles  and  dock 
timbers,  leaving  hardly  any  part  within  their  range  unperfor- 


AND    FOUNDATION    WALLS.  3! 

ated,  but  the  tubular  track  of  one  never  pierces  across  the  tube 
bored  by  another  worm.  Their  instinct  teaches  them  scrupu- 
lous respect  for  each  other's  way.  In  a  period  of  less  than  four 
years  they  will  destroy  the  piles.  And  there  are  worms  that 
wield  their  mandibles  with  such  extraordinary  power  as  even  to 
bore  into  solid  rock. 

In  the  lower  part  of  the  Sacramento  river,  just  above  where 
it  enters  Suisune  Bay,  the  banks  at  low  tide  expose  all  along  for 
one  or  two  miles  innumerable  hard,  compact  sand-boulder  rocks. 
In  carrying  a  military  survey  along  these  banks,  I  observed  in 
hundreds  of  the  rocks  deep  tublar  holes  of  from  one-half  to 
three-eighths  inch  in  diameter,  running  straight  in,  some  to  the 
depth  of  eighteen  inches.  Every  hole  was  lined  with  a  perfect 
•coating  of  beautiful  white  enamel  as  hard  as  glass.  At  the  bot- 
tom of  each  hole  there  was  invariably  a  worm  found,  who  had 
bored  for  himself  a  habitation  into  the  rock.  These  extraordi- 
nary mandibular  worms,  if  not  the  same  kind,  are  about  the 
same  size,  I  judged,  as  the  smaller  kind  of  salt  water  borers 
called  limnoria. 

The  piles  used  in  the  San  Francisco  waters,  are  chiefly  Ore- 
gon spruce  and  Oregon  pine.  An  antiseptic  that  will  preserve 
wood  there  will  not  fail  to  be  favorably  received. 

New  processes  for  preserving  timber  are  being  constantly  in- 
troduced. Prof.  Chas.  A.  Seely  and  W.  T.  Pelton  are  the 
patentees  of  some  processes. 

The  method  of  application  patented  by  Professor  Charles  A. 
Seely,  of  New  York,  in  1867,  is  a  modification  of,  and  an  un- 
doubted improvement  upon  Bethel's  process,  in  being  applicable 
to  green,  water-logged  wood,  and  with  far  more  efficiency  even 
to  seasoned  wood,  differing  materially,  however,  in  the  mode  of 
application  of  the  dead  oil,  This  new  process  consists  of  im- 
mersing the  wood  in  a  closed  iron  tank  of  the  oil,  raising  the 
whole  to  a  temperature  between  212°  and  3OO°F.  This  action 
is  allowed  to  go  on  until  the  moisture  or  water  contained  in  the 
wood  is  expelled,  or  has  escaped  in  the  shape  of  steam.  The 
water  being  supposed  thus  expelled,  and  the  pores  containing 
little  or  no  steam,  the  hot  oil  is  suddenly  replaced  by  a  bath  of 
cold  oil,  condensing  all  the  remaining  steam,  and  thereby  leav- 
ing a  total  or  partial  vacuum  in  the  wood  cells,  into  which  the 


32  POWELL  S   FOUNDATIONS 

oil  immediately  rushes,  impelled  by  the  hydrostatic  pressure  of 
the  oil,  and  the  pressure  of  the  atmosphere,  favored  also  by 
capillary  attraction. 

Those  who  favor  this  process  claim  for  it  the  following  re- 
sults: 

ist.  The  effect  of  the  hot  bath  is  to  sufficiently  season  the 
wood,  and  destroy  or  coagulate  all  the  albumen  and  expel  the 
water  and  other  fluids  from  the  pores. 

2d.  The  effect  of  the  cold  bath  is  to  impregnate  the  wood 
cells  with  the  antiseptic  (carbolic  acid),  and  at  the  same  time 
stuff,  as  it  were,  the  pores  that  will  for  a  long  time  after  expos- 
ing the  timber  to  the  air,  variations  of  atmospheric  tempera- 
ture, soil,  rain,  salt  or  fresh  water,  resist  absorption  of  destruct- 
ive agents  from  all  these  sources,  the  borers  in  salt  water, 
worms  on  land,  and  white  ants  in  tropical  climates  inclusive ; 
and  also  prevent  the  rusting  of  iron  bolts,  spikes,  nails,  etc.,, 
that  may  be  driven  in  the  treated  wood. 


AND   FOUNDATION   WALLS.  33 


CHAPTER  III. 

Excavations. 

Under  this  heading  it  is  thought  best  to  give  abstracts  of  a 
revised  ordinance  of  New  York  City,  relative  to  the  Construc- 
tion of  Vaults  (similar  laws  in  reference  to  vaults  and  areas 
should  exist  in  other  cities)  with  the  rates  to  be  paid  on  per- 
mits, i.  e. : 

"A  permit  must  be  taken  out  before  excavation,  or  legal  pro- 
ceedings will  be  instituted  against  the  owner  or  builder." 

"SEC.  i.  Empowers  the  Department  of  Public  Works  to 
grant  permits  for  the  construction  of  vaults  in  the  streets,  pro- 
vided, in  their  opinion,  no  injury  will  come  to  the  public  there- 
by. 

"SEC.  2.  Forbids  the  construction  of  vaults  in  any  street  in 
the  City  of  New  York  without  permission  in  writing  from  said 
board,  under  the  penalty  of  one  hundred  dollars. 

"SEC.  3.  Applicants  for  permits  must  state  the  name  of  the 
owner  of  the  premises  in  front  of  which  the  vault  is  to  be  built ; 
the  purposes  for  which  the  building  is  or  is  intended  to  be  used  ; 
the  number  of  square  feet  to  be  occupied  by  the  vault,  includ- 
ing its  walls  ;  and  the  proposed  length  and  width  of  the  same. 

"Rule  required  to  be  complied  with:  —  When  applications  for 
vaults  are  made,  such  applications  shall  in  all  cases  be  accom- 
panied by  a  plan  drawn  upon  a  scale  of  one-fourth  of  one  inch 
to  one  foot,  showing  the  whole  area  to  be  built,  including  walls, 
and  designating  the  open  area,  if  any,  and  also  the  space  to  be 
exclusively  used  for  stairways  (see  Sec.  1 5) ;  and  in  case  there 
shall  be  any  fire  hydrant  in  front  of  premises  where  the  vault  is 
to  be  excavated,  the  position  of  such  hydrant  shall  be  shown  on 
such  plan,  and  there  shall  be  a  space  of  two  feet  left  around  the 
hydrant. 


34  POWELL'S  FOUNDATIONS 

.  "SEC.  4.  Requires  that  payment  for  each  square  foot  of 
ground  to  be  occupied  by  the  vault  shall  be  made  on  obtaining 
the  permit,  under  the  penalty  of  one  hundred  dollars. 

"SEC.  5.  Prohibits  the  construction  of  vaults  beyond  the 
line  of  sidewalks  or  curbstone,  under  the  penalty  of  two  hun- 
dred and  fifty  dollars.  //  is  to  be  distinctly  understood  that  the 
permit  gives  no  authority,  and  it  is  strictly  forbidden,  to  disturb, 
by  excavation  or  otherwise,  any  water  hydrant,  or  stop-cock,  or 
stop-cock  chamber,  or  water  pipe  ;  or  do  anything  to  prevent 
the  proper  use  of  any  hydrant  or  stop-cock,  or  expose  them  to 
freezing. 

"SEC.  6.  Makes  it  the  duty  of  the  person  obtaining  a  per- 
mit to  deliver  to  this  board  a  certified  measurement  by  one  of 
the  city  surveyors  of  the  ground  occupied  by  the  vault  before 
the  same  is  covered,  under  the  penalty  of  one  hundred  dol- 
lars. 

"SEC.  7.  If  it  appears  by  such  certificate  that  the  vault  oc- 
cupies a  greater  number  of  square  feet  than  shall  have  been 
paid  for,  the  owner  of  such  vault,  and  the  master  builder  under 
whose  direction  the  same  shall  be  constructed,  shall,  in  addition 
to  the  penalty  imposed  in  and  by  section  4,  severally  and  re- 
spectively forfeit  and  pay  twice  the  sum  previously  paid,  for 
each  square  foot  of  ground  in  excess  of  the  number  of  square 
feet  previously  paid  for. 

"SEC.  10.  During  the  time  of  constructing  vaults  a  lamp  or 
lantern  shall  be  kept  burning  the  whole  of  every  night,  which 
shall  be  placed  so  as  to  cast  its  light  upon  the  opening,  under 
the  penalty  of  ten  dollars. 

"SEC.  ii.  All  vaults  must  be  completed  and  the  ground 
closed  over  them  within  three  weeks  after  they  are  commenced, 
under  the  penalty  of  five  dollars  for  each  day  they  may  remain 
uninclosed  after  that  period. 

"SEC.  12.  No  area  in  the  front  of  any  building  in  the  City  of 
New  York  shall  extend  more  than  one-fifteenth  part  of  the 
width  of  any  street,  nor  in  any  case  more  than  five  feet, 
measuring  from  the  inner  wall  of  such  area  to  the  building ;  nor 
shall  the  railing  of  such  area  be  placed  more  than  six  inches 
from  the  inside  of  the  coping  on  the  wall  of  such  area,  under 


AND    FOUNDATION    WALLS.  35 

the  penalty  of  two  hundred  and  fifty  dollars,  to  be  recovered  from 
the  owner  and  builder  thereof  severally  and  respectively. 

"SEC.  14.  Every  description  of  opening  below  the  surface  of 
the  street  in  front  of  any  shop,  store,  house  or  other  building, 
if  covered,  shall  be  considered  and  held  to  be  a  vault  within  the 
meaning  of  this  chapter,  and  the  master  builder,  or  owner,  or 
person  for  whom  the  same  shall  be  made  or  built,  shall  be  liable 
to  the  provisions,  payments  and  penalties  of  this  chapter  sever- 
ally and  respectively. 

"SEC.  15.  The  last  preceding  section  of  this  chapter  shall 
not  be  constructed  to  refer  to  those  openings  which  are  used 
exclusively  as  places  for  descending  to  the  cellar  floor  or  any 
building  or  buildings  by  means  of  steps. 

"Payments  for  vault  permits  must  be  made  on  taking  out  the 
permit,  as  follows,  viz.  : 

"For  permission  to  construct  a  vault  in  front  of  any  building, 
seventy-five  cents  per  square  foot. 

"Where  it  is  proposed  to  increase  the  superficial  area  of  any 
vault,  the  increased  area  is  only  to  be  paid  for  at  the  above 
rates.  In  such  case  the  surveyor  certifying  to  the  dimensions 
of  the  new  vault  must  also  certify  to  the  dimensions  of  the  old 
vault. 

"It  will  be  seen  by  section  14  that  excavations  commonly 
known  as  areas  or  parts  of  areas,  if  covered,  are  to  be  paid 
for  as  vaults,  excepting  such  space  only  as  may  be  occupied  by 
steps  for  descending  to  the  basement  or  cellar  floor." 

The  preceding  laws  in  reference  to  vaults  and  areas  are  very 
effective  in  New  York,  and  similar  laws  should  exist  in  all  cities 
to  protect  the  owners  of  property,  pedestrians,  vehicles,  and 
business  generally  during  the  construction  of  buildings. 

A  further  permit  is  required  before  excavation  and  the  com- 
mencement of  work  in  the  foundations.  This  permit  has  to  be 
obtained  from  a  Board  known  as  the  Department  of  Buildings 
in  the  City  of  New  York.  Some  other  large  cities  in  the  United 
States  have  Department  of  Buildings  or  some  laws  that  strictly 
pertain  to  buildings.  The  requisite  information  in  regard  to 
the  New  York  laws  on  this  subject  will  be  given  under  the 
heading  of  Walls,  etc. 


36  POWELL'S  FOUNDATIONS 

Excavations.  —  Twenty-four  cubic  feet  of  sand  ;  or,  seven- 
teen cubic  feet  of  clay  ;  or,  eighteen  cubic  feet  of  earth  ;  or, 
thirteen  cubic  feet  of  chalk,  equal  one  ton.  One  cubic  yard  of 
earth  before  digging  will  occupy  about  one  and  one-half  cubic 
yards  when  dug,  and  contains  twenty-one  struck  bushels,  and  is 
considered  a  single  load  ;  or,  double  this  a  double  load. 

Footings  and  Footing  Conrses.  —  In  commencing  the  erection 
of  any  building  it  is  usual  to  spread  the  bottom  courses  of  the 
masonry  beyond  the  inner  and  outer  face  of  the  walls  ;  the 
spread  courses  are  termed  footings,  and  distribute  the  weight  of 
the  structure  over  a  larger  area  of  bearing  surface  ;  the  liability 
to  vertical  settlement  from  the  compression  of  the  ground  is 
greatly  diminished. 

In  the  case  of  isolated  buildings  standing  on  a  small  base, 
they  give  a  great  protection  and  resist  the  force  of  high  winds, 
storms,  etc. 

For  instance,  take  the  case  of  a  chimney  shaft  one  hundred 
feet  hi^h,  standing  on  a  base  ten  feet  square,  and  exposed  to 
heavy  gales.  The  compression  of  the  ground  from  the  force  of 
the  wind  that  would  cause  a  depression  of  one-quarter  of  one 
inch,  would  cause  the  chimney  to  be  out  of  centre  five  inches. 
If  the  base  is  increased  to  twenty  feet  square,  we  not  only  in- 
crease the  leverage  to  resist  the  force  of  the  wind,  but  the  sus- 
taining surfao,e  is  quadrupled ;  so  that  the  resistance  is  eight 
times  greater  than  in  the  first  instance.  Footings,  to  be  effect- 
ive, must  be  bonded  into  the  body  of  the  work,  and  of  suffi- 
cient strength  to  resist  the  cross-strains  to  which  they  are  ex- 
posed. It  is  a  common  practice  among  mason  builders,  whether 
the  materials  be  of  brick  or  stone,  to  simply  comply  with  the 
requirements  of  the  plans,  lay  the  footings  down,  pay  no  regard 
to  bonding,  and  leave  the  unequal  settlement  of  the  walls  to 
chance.  This,  of  course,  does  not  occur  with  men  skilled  in 
their  trades. 

In  Building  large  Chimneys  for  Manufactories,  the  size  of  the 
chimneys  and  the  height  should  be  determined  by  proper  experts, 
and  with  the  opinion  of  the  Engineers. 

Rules  for  Chimneys  :— The  area  of  the  chimney  should  be 
three-quarters  that  of  the  opening  over  the  bridge ;  viz  :  one  and 


AND    FOUNDATION   WALLS.  37 

one-half  inch  per  pound  of  coal  consumed  ;  or,  nineteen  and  one- 
half  inches  for  each  foot  of  fire  surface  burning  thirteen  pounds 
per  hour.  The  whole  diminution  of  flue  should  be  gradual,  and 
not  by  any  offsets.  A  common  rule  for  size  of  chimneys  is,  that 
the  minimum  area  of  chimneys  twenty-four  to  thirty  yards  high 
is  four  hundred  square  inches  for  each  twenty  horse  power. 

Chimneys  of  any  considerable  height  should  be  tied,  clamped, 
or  anchored  with  wrought  iron  straps,  etc.,  at  not  less  than  every 
twenty-five  feet  in  height. 

The  highest  chimney  stack  in  England  is  at  Bolton ;  it  is  367 
feet  taken  from  the  surface  of  the  earth,  octagonal  in  plan,  14 
feet  on  each  side,  and  112  feet  girth  at  bottom.  Thickness  of 
brickwork  at  bottom,  8  feet ;  thickness  of  brickwork  at  top,  I 
foot  6  inches ;  5  feet  6  inches  on  each  side  at  top,  or  44  feet 
girth.  The  top  is  finished  with  stone. 

The  chimney  of  the  Edinburgh  Gas  Works  is  341  feet  6  inches 
high.  It  is  329  feet  from  the  surface  of  the  earth.  Stone  foun- 
dations 40  feet  6  inches,  by  6  feet  6  inches  deep  ;  30  feet  square 
at  ground  line,  27  feet  9  inches  square  at  top  of  stone  pedestal ; 
on  top  of  this  the  brick  shaft  is  264  feet  high ;  26  feet  at  the 
bottom  diameter,  and  1 5  at  the  top. 

In  the  construction  of  large  chimneys,  and  particularly  isola- 
ted ones,  they  should  be  built  with  great  care,  the  mortar  be- 
ing prepared  every  day,  of  one  of  lime  to  two  parts  of 
sharp  sand ;  or,  of  cement  and  sand.  The  masons  should 
change  positions  and  level  and  true  the  work  often,  to  equalize 
the  difference  in  the  work  done  by  different  men ;  select  com- 
petent men  for  the  work. 

The  Foundations  and  Trenches  for  Footings  should  be  cleared 
of  all  rock,  rubbish  or  soil,  and  leave  the  site  of  the  intended 
building  clear  and  unincumbered  ;  and  make  perfectly  level  and 
hard  the  bed  of  all  trenches,  and  consolidate  the  earth  about 
the  same. 

Foundations  in  cities  are  usually  excavated  according  to  the 
survey  furnished  by  one  of  the  City  Surveyors.  Outside  of  the 
city,  for  suburban  or  country  buildings,  the  excavations  are  gen- 
erally made  direct  from  the  plans.  After  the  earth  is  removed, 
either  in  city  or  country,  it  is  necessary  to  lay  out  the  base-walls 


38  POWELL'S  FOUNDATIONS 

of  the  structure  with  lines,  secured  to  stakes  driven  in  the  ground. 
The  common  method  is  to  establish  one  line,  call  it  a  base  line, 
running  parallel  with  the  street  line  curb  or  fence  line,  as  the 
case  may  be.  From  this,  where  no  side-walls  control  the  lines 
of  the  building,  it  may  be  necessary  to  produce  a  line  square, 
and  at  right-angles  to  the  base  line,  which  is  usually  done  thus  : 
*  Draw  the  line  tight,  and  as  near  a  right  angle  to  the  base  line 


C, 


ILLUSTRATION  8. 


as  possible  ;  then  true  it  by  using  a  rod  laid  off  in  feet.  After 
you  have  commenced,  and  have  a  long  line  to  square,  it  may  be 
necessary  to  increase  the  triangle  in  laying  out  to  twelve  feet, 
sixteen  feet  and  twenty  feet.  After  this  the  square  may  be 
tested  on  the  lines  by  using  a  rod  thus  : 


ILLUSTRATION  9. 

Take  any  angle,  A,  B  and  C,  on  one  side  with  three  measure- 
ments, and  try  the  same  on  the  other  side.  This  has  to  be 
tested  very  carefully.  Some  masons  have  large  wooden  squares 


A  Leveling  Instrument  is  now  manufactured  especially  for  this  purpose. 


AND    FOUNDATION   WALLS. 


39 


for  the  purpose,  the  use  of  which  is  better  than  deciding  by 
sight,  or  even  measuring  on  the  line. 

Another  method  of  getting  a  right-angle  :  To  erect  a  perpen- 
dicular line  at  any  point  on  the  base  line  A  B,  set  one  point  of 
compass  or  rod  to  sweep  a  radius  at  B,  and  describe  the  arc  of  a 
circle ;  use  the  same  radius,  and  put  one  point  at  I,  and  inter- 
sect the  line  at  2,  then  produce  a  line  from  I  to  2.  Use  2  as  a 
centre  of  same  radius,  and  draw  a  curve,  then  produce  and  con- 


\ 


ILLUSTRATION  10. 


tinue  the  line  I  to  2  to  3.  Then  draw  the  line  from  B  to  3,  and 
this  gives  the  desired  angle.  After  this  is  done  once  or  twice, 
it  is  very  simple.  Circles,  polygons  or  ellipses  are  best  when 
laid  out  on  a  wooden  template. 

It  is  best  in  laying  out  lines  for  excavations  to  set  the  stakes 
at  some  distance  from  where  the  earth  or  debris  is  being  re- 
moved, and  to  test  the  exact  angles,  by  diagonal  measurement : 
— This  must  be  done  accurately  even  if  a  little  more  time  is  re- 
quired ;  as  soon  as  this  is  done  it  is  important  to  establish  the 
grade  line. 

To  make  a  right  angle  or  perpendicular  line  :  Divide  the  given 
line  A,  B,  into  two  equal  parts,  and  draw  a  perpendicular  line 
as  shown  on  the  illustration  No.  1 1.  From  the  points  A  and  B 
as  centres  and  with  any  radius  greater  than  one-half  A  B  de- 
scribe the  two  arcs  C  and  D,  then  draw  a  line  through  E  to  F. 
The  line  E  F  will  be  at  right  angles  to  A  B.  This  may  be  used 
where  it  is  necessary  to  lay  out  a  large  square  or  lines  for  centres. 


POWELL'S  FOUNDATIONS 


ILLUSTRATION  n. 

To  draw  an  Octagon  in  a  given  square.  From  each  corner 
of  a  square,  and  with  a  radius  equal  to  half  its  diameter  A  to  B, 
describe  the  four  arcs ;  and  join  the  points  at  which  they  cut  the 
corners  of  the  square.  Illustration  12. 


ILLUSTRATION  12. 

Springs  in  Cellars,  etc. — After  excavations  are  made  for  a 
building,  either  in  city  or  country,  there  is  often  found  a  small 
water-course  or  spring.  In  the  country  it  is  best  to  tap  the 
spring  or  line  of  water-course  outside  of  the  building,  and  take 
it  away  from  the  building,  and  follow  a  course  that  will  prevent 
its  returning  and  undermining  the  walls.  In  cases  where  this 
cannot  be  done  in  the  city  or  country,  sink  and  build  with  rough 
stone  such  size  cistern  as  may  be  required  for  a  flow  of  water 
for  three  or  four  days,  and  carefully  build  a  drain  from  cistern, 
following  the  line  of  water-course  to  outside  wall,  if  possible. 

If  there  is  an  overflow  liable  to  occur  from  freshets,  tides, 
rain,  etc.,  and  the  cellar  bottom  is  below  the  line  of  sewer,  it 
may  be  considered  the  best  to  build  cemented  cisterns  that  will 


AND   FOUNDATION   WALLS.  4! 

fill  to  a  certain  height  and  have  an  indicator  to  prevent  overflow 
or  rise  of  water.  These  may  be  emptied  by  using  a  small  force- 
pump. 

If  a  cellar  bottom  is  located  in  low  ground,  or  below  adjoining 
cellars,  and  a  supply  of  water  seems  to  permeate  the  soil,  and 
accumulate,  it  is  not  safe  to  use  any  steam-pump,  as  it  may  draw 
water  from  the  surroundings,  and  weaken  the  foundation  walls, 
unless  due  precaution  has  been  taken  in  building.  Ordinary 
cisterns  and  hand-force  pumps  seem  to  act  the  best  in  such 
cases,  by  pumping  water  into  a  waste-pipe  to  be  carried  into 
sewer.  If  there  is  no  waste-pipe,  then  it  has  to  be  pumped  to 
such  height  that  it  may  be  emptied.  Where  a  large  spring  or 
water-course  is  found  on  the  cellar  line  of  large  structures,  it  is 
necessary  to  collect  by  drains  all  the  water  into  a  cemented  cis- 
tern, and  attach  to  the  engine  used  in  building  a  small  pump 
of  sufficient  capacity  to  keep  the  water  below  a  fixed  line  forty- 
eight  hours,  to  prevent  an  overflow. 

As  a  rule  the  surface  of  cellar  bottoms  should  be  covered 
with  concrete,  ranging  from  four  to  twelve  inches  in  thickness, 
to  form  a  smooth  floor  surface.  Those  that  are  wet  or  damp 
(and  nearly  all  are  more  or  less  so)  should  have  a  layer  of  as- 
phaltum  over  the  surface,  and  extended  up  the  sides  to  a  point 
above  where  the  dampness  arises  (see  illustrations  36  and  38). 
The  asphaltum,  when  used,  should  be  protected  by  laying  on  it 
a  course  of  bricks,  bedded  in  cement,  or  an  additional  layer  of 
cement.  If  a  smooth,  handsome  surface  is  desired,  Portland 
cement  should  be  used  for  the  finish.  Rosendale  and  many 
American  cements  of  the  best  quality  may  be  used,  and  bricks 
coated  with  asphaltum  are  often  used. 


PROPERTY  OF 
DONAHUE, 


POWELL'S  FOUNDATIONS 


CHAPTER  IV. 

FOOTINGS  —  STONE  AND   BRICK.    STRENGTH  OF  STONES  AND 
METHODS  OF  OBTAINING  SECURE  FOUNDATIONS. 

Stone  Foundations,  Walls.— The  bottom  stones  of  course 
sustain  the  load  or  weight  of  the  building,  and  hence  the 
greater  the  risk  arising  from  any  irregularities  in  the  bedding 
of  the  stone.  To  avoid  this,  the  stone  should  be  dressed  true, 
no  spalls  used,  and  properly  bedded.  In  New  York  City  the 
foundation  or  base  stones — nearly  all  of  which  come  from  quar- 
ries on  the  island — are  of  Gneiss,  a  kind  of  granite,  which  crops 
out  above  the  surface  in  irregular  strata.  The  others  are  com- 
mon building  stone,  and  a  blue  kind  of  limestone. 

No  back  joints  should  be  allowed  beyond  the  face  of  the  up- 
per work,  except  where  the  footings  are  in  double  courses,  and 
every  stone  should  bond  into  the  body  of  the  work  several 
inches  at  least.  Unless  this  is  attended  to,  the  footings  will 
not  receive  the  weight  of  the  superstructure  and  will  be  useless. 
See  111.  13. 


ILLUSTRATION  13. 

In  fixing  the  spread  of  the  footings  or  foundation  courses  of 
the  masonry  or  brick-work  of  ordinary  walls  the  usual  rule  is  to 
make  the  breadth  of  the  base  one  and  one-half  the  thickness  of 


AND   FOUNDATION   WALLS.  45 

the  body  of  the  wall  on  compact  gravel,  and  twice  that  thick- 
ness on  sand  or  stiff  clay. 

The  following  principles  should  in  all  cases  be  observed  in  the 
building  of  all  kind  of  stone  masonry  :  To  build  the  masonry  as 
far  as  possible  in  a  series  of  courses  perpendicular  to  the  direc- 
tion of  the  pressure  they  have  to  sustain  ;  avoid  all  continuous 
joints  and  break-joints  ;  use  the  largest  stones  for  the  foundation 
courses  ;  lay  all  stones  with  layers  or  beds  so  that  the  pressure 
will  act  directly  perpendicular  to  the  direction  of  the  layers ;  *. 
e.y  by  laying  the  stone  on  its  natural  bed.  This  is  of  primary  im- 
portance to  strength  and  durability. 

Moisten  the  surface  of  dry  and  porous  stone  before  bedding 
it,  which  prevents  the  mortar  from  drying  too  fast,  and  being 
reduced  to  powder  by  the  stone  absorbing  its  moisture.  Fill  all 
the  joints  and  all  spaces  between  the  stones  with  mortar ;  have 
such  spaces  as  small  as  possible. 

Stone-work  is  estimated  by  the  perch  of  twenty-five  cubic  feet, 
01  by  the  cubic  foot. 

Brick  for  Foundation  Footings,  etc. — The  following  are  the 
principles  to  be  observed  in  building  with  brick : 

First.  Reject  all  bad  shaped  and  unsound  bricks.  Good  bricks 
are  regular  in  shape,  with  plane  surfaces  and  sharp,  true  angles. 
They  give  a  clear  ringing  sound  when  struck.  When  broken, 
they  show  a  compact,  uniform  structure.  Should  not  absorb 
more  than  one-fifteenth  their  weight  in  water. 

Second.  Place  the  beds  of  the  courses  perpendicular  to  the 
pressure  which  they  sustain.  Make  the  bricks  in  each  course 
break-joint  with  those  of  the  courses  above  and  below,  by  over- 
lapping from  one-quarter  to  one-half  of  the  brick.  Cleanse  the 
bricks,  wet  them  thoroughly  before  laying  to  avoid  absorbing 
the  moisture  in  the  mortar  too  rapidly.  Fill  all  the  joints  with 
mortar,  taking  care  that  the  mortar  shall  not  exceed  one-quarter 
of  one  inch  in  thickness  ;  lay  four  courses  to  ten  inches,  or  four 
courses  to  twelve  inches,  accordingly  as  you  use  different  thick 
nesses  of  brick,  and  then  only  allow  one-quarter  inch  for  each 
joint.  Use  no  bats  or  pieces  of  bricks. 

The  volume  of  mortar  required  for  good  brick-work  is  about 
one-fifth  of  the  volume  of  the  bricks. 


44 


POWELL  S    FOUNDATIONS 


English  bond  (Illus.  14)  in  brick-work  is  considered  the  strong- 
est    It  consists  in  laying  entire  courses  of  headers  and  stretch- 

i  ~~  ,        i . 


i  i  i  ii  ii  ii  ii  i 

ILLUSTRATION  14. 

•ers  periodically;  the  proportion  here  shown  is  one  course  of 
headers  to  two  of  stretchers. 

In  ordinary  walls  it  is  usual  to  lay  one  course  of  headers  to 
four  of  stretchers.  Flemish  bond  in  brick-work  is  a  header  and 
stretcher  laid  in  each  course ;  thus:  (Illus.  15.) 


ILLUSTRATION  15. 

This  presents  a  very  neat  appearance,  but  it  is  not  considered 
as  strong,  where  a  question  of  strength  arises,  as  the  English 
bond. 

In  building  a  factory  chimney  the  longitudinal  tenacity  is  more 
important  than  the  transverse ;  and  it  is  best,  in  cases  of  this 
kind,  to  have  four  stretchers  to  one  of  headers. 

Brick-work  is  estimated  by  the  thousand,  and  also  by  the  cu- 
bic foot.  Walls  vary  slightly  in  thickness,  owing  to  the  sizes 
of  the  brick ;  but  the  superficial  quantity  is  the  same. 

TABLE  OF  BRICK-WORK. 

8  or  9  inch  wall,  1      brick  thick,  14  bricks  to  the  superficial  foot. 

12  or  13  "         "      11-2  "         "  21       "       "  "  " 

16  or  18  "         "     2         »         "  28       "       "  "  " 

20  or  22  "         "     21-2  "         "  35       "       "  "  " 


The  best  Philadelphia  and  Baltimore  bricks  are  eight  and  one- 


AND   FOUNDATION   WALLS.  45. 

half  inches  long  by  four  and  one-quarter  inches  wide,  by  two 
and  one-half  inches  thick. 

The  Baltimore  front  and  wall  brick  is  the  same  size  as  the 
Philadelphia.  The  average  size  New  York  brick  is  eight  inches 
in  length,  four  inches  wide,  and  two  and  one-quarter  inches  thick, 
and  is  mostly  made  up  the  North  River.  Inferior  grades  of 
brick  are  made  eight  inches  long,  three  and  one-half  wide, 
and  two  and  one-half  thick,  and  some  of  them  sold  in  the  New 
York  market  are  unfit  for  sound  walls.  The  Croton  North  River' 
brick  measures  eight  inches  by  three  and  three-quarters  wide, 
by  two  and  one-quarter  inches  thick ;  average  when  laid,  four 
courses,  including  mortar,  to  ten  inches.  The  very  handsome 
white  brick  for  ornamental  purposes,  from  Perth  Amboy,  is 
eight  and  one-quarter  inches  long,  four  and  one-eighth  inches 
wide,  and  two  and  one-quarter  inches  thick.  The  Trenton, 
New  Jersey  brick  is  eight  and  three-eighths  inches  long,  four 
inches  wide,  and  two  and  three-eighths  inches  thick.  The  En- 
ameled-faced  bricks  made  in  New  Jersey  are  buff,  brown,  black 
cream,  and  blue  in  color,  and  are  eight  inches  long,  four  inches 
wide,  and  two  and  one-half  thick.  Hollow  burned  brick,  used 
for  hollow  brick  walls  and  inside  firring  of  various  sizes,  are  : 

Single,  8  inches  long,  3  5-8  inches  wide,  by  2 1-4  inches  thick ; 
Double,  8     "        "        71-2     "         "      "   41-2      "        " 
Treble,  8     "        "        7 1-4     "         "      "    7 1-4      "        " 

Hollow  arch  bricks  are  about  71-4x7  1-4,  beveled  for  arches, 
and  of  various  sizes. 

Use  of  Stone  for  Building  Purposes.— "M.  Viollet-le-Duc  has 
told  us  how  the  mediaeval  constructors  made  it  a  rule  to  place 
stone  upon  their  beds ;  how  in  buttresses,  arches,  and  vaulting 
of  different  kinds  the  stones  were  so  laid  as  to  receive  the  thrust 
obliquely  or  laterally  upon  their  beds  ;  and  how  they  employed 
only  certain  stones  capable  of  great  powers  of  endurance  which 
are  less  easily  delaminated — i.  e.  liable  to  scale  off  in  layers — when 
so  fixed.  About  thirty  years  ago  the  late  Mr.  C.  H.  Smith,  who 
had  thoroughly  studied  the  subject  of  lithology,  said  that  the 
importance  of  laying  stones  in  buildings  upon  their  beds  was 
generally  over-rated,  and  that  it  signified  little  which  way  a  stone 
was  laid  unless  it  presented  a  decidedly  laminated  structure. 


46  POWELL'S  FOUNDATIONS 

We  unhesitatingly  maintain  that  soft,  calcareous  or  limestone 
should  be  laid  in  the  walls  of  a  building  upon  its  natural  bed, 
and  that  the  beds  should  not  be  exposed  to  inclement  weathei 
after  they  have  been  dressed. 

It  is  by  no  means  certain  that  porous  stones  are  inferior  be- 
cause of  their  porousness. 

If  stone  easily  soaks  up  water  it  also  easily  ejects  it.  Damp- 
ness attacking  a  stone  wall  from  the  outside  is  infinitely  less  de- 
structive than  that  which  attacks  it  from  the  inside.  Provided 
the  action  be  free  from  the  outside  to  the  inside  and  not  from 
the  inside  to  the  outside  of  a  stone  the  moisture  does  not  serious- 
ly injure  it.  Soft  stones  for  years  impregnated  with  dampness 
have  not  decomposed  even  though  laid  in  the  basement  walls  of 
a  building.  Certain  stones  which  decompose  after  exposure  to 
the  air  remain  intact  in  water  or  damp  earth.  Stone  is  much 
more  likely  to  decay  in  damp  and  sheltered  situations  than  when 
it  is  exposed  to  the  full  action  of  atmospheric  influences ;  but 
this  should  be  "read  between  the  lines"  because  in  damp  situa- 
tions stone  is  not  always  subject  to  decay.  If  the  exposed  face 
of  the  stone  dries  and  leaves  the  heart  of  the  stone  unnaturally 
wet  the  internal  moisture  will  ultimately  crystallize  upon  the 
surface,  and  during  this  process  a  certain  amount  of  decomposi- 
tion will  take  place  in  the  stone  itself. 

But  if  the  stone  be  so  placed  as  to  permit  the  moisture  it  has 
received  from  the  outside  to  be  drawn  away  from  it  in  a  fluid 
state  its  component  parts  will  not  suffer  vital  deterioration. 

Limestones  suffer  quick  deterioration  when  placed  next  to 
certain  sandstones.  Various  kinds  of  lime  and  cement  eat  in- 
to soft  calcareous  stone,  which,  besides,  contains  within  itself 
the  elements  of  its  own  destruction  ;  and  dampness  insidiously 
admitted  will  set  in  motion  these  elements  of  change  which  in 
a  latent  state  are  harmless. 

Rondelet — totally  ignoring  the  fact  that  in  architecture  peo- 
ple prefer  to  spend  as  little  money  as  possible  except  on  exter- 
nal show — advises,  under  similar  circumstances,  the  use  of  scin- 
tillant  or  ignescent  stones,  i.  e.  those  which  emit  sparks  of  fire 
when  struck  with  steel,  because  they  effervesce  on  the  applica- 
tion of  the  principle  acids  ;  some  kinds  however  will  resist  the 
action  of  fire.  Calcareous  stone  is  that  which  is  the  most  abun- 


AND    FOUNDATION   WALLS.  47 

dantly  found  upon  the  surface  of  the  globe.  It  is  homogeneous, 
easily  quarried  and  wrought  and  it  adheres  to  mortar.  It  is 
perfectly  well  known  that  under  certain  acids,  even  vegetable 
acids,  these  calcareous  stones  effervesce  and  disintegrate  ;  and 
that  under  the  action  of  fire  they  are  converted  into  quick  lime 
and  carbonic  acid.  It  has  also  been  observed  that  a  species  of 
spider,  microscopic  in  size,  is  a  fertile  agent  of  destruction. 
These  insects  spin  their  webs  in  the  almost  imperceptible  cavi- 
ties which  abound  in  limestones  ;  dust  rests  upon  them  and  moist- 
ure of  all  kinds  is  thus  attracted,  and  this,  with  the  incessant 
labours  of  the  insects  themselves,  is  one  of  the  causes  of  deterio- 
ration. (This  does  not  often  occur  in  this  country.)  We  have  still 
to  allude  to  an  important  fact  connected  with  stone  of  nearly  all 
kinds.  A  natural  action  takes  place  in  the  majority  of  lime- 
stones immediately  upon  their  extraction  from  the  quarry  and 
exposure  to  the  air.  This  action,  which  in  most  cases  is  vital 
in  its  effects  and  certain  in  its  results  if  properly  encouraged, 
should  not  be  ignored  by  architects  and  builders.  The  half  hard 
and  soft  stones  harden  after  their  extraction. 

All  calcareous  stones  originally  contain  a  certain  quantity  of 
water  which  is  known  as  quarry  water.  Some  kinds  are  only 
a  step  removed  from  soft  stone,  and  form  upon  their  surface 
a  crest  or  covering  almost  impossible  to  penetrate  with  the  chis- 
el ;  while  at  the  depth  of  half  an  inch  the  stone  may  be  scratch- 
ed with  the  thumb  nail.  This  crust  is  the  result  of  the  evapora- 
tion of  the  quarry  water.  This  water  coming  to  the  surface  of 
the  stone  brings  with  it  a  certain  quantity  of  dissolved  carbonate 
of  lime  which  crystallizes  and  forms  the  crust  above  referred 
to.  It  is  twice  as  easy  to  work  stone  with  quarry  water  in  it  as 
it  is  when  the  water  has  evaporated  ;  but  this  is  only  possible  in 
certain  climates  and  seasons. 

Water  freezing  within  the  pores  of  a  stone  must  exercise  a 
disintegrating  action  ;  and  this  action  often  completely  destroys 
the  stone  for  building  purposes  when  quarried  in  the  winter 
and  exposed  to  the  influence  of  frost. 

In  the  Use  of  Stone  for  Building  Purposes  and  Walls  generally, 

it  is  important  that  the  architect  and  builder  should  have  a  fair 
knowledge  of  rocks  and  the  quarries  from  whence  the  stones 


48  POWELL'S  FOUNDATIONS 

are  obtained ;  hence,  there  is  herewith  given  some  concise  defi- 
nitions of  oxides,  and  the  formation  of  various  Rocks  found  and 
in  use  for  Building  purposes  generally. 
Lime  is  oxide  of  calcium. 
Soda  is  oxide  of  sodium. 
Silica  or  Quartz  is  oxide  of  silicum. 
Alumina  is  oxide  of  aluminum. 

Rocks  :^-Feldspar  is  a  double  silicate  of  alumina  and  an  alkali ; 
there  are  many  varieties,  and  it  is  nearly  as  hard  as  quartz. 

Hornblende  is  a  double  silicate  of  iron  and  alumina  :  it  is  slaty 
in  structure,  but  generally  a  mass  of  prismatic  crystals,  some- 
times fibrous,  but  not  elastic.  Among  the  varieties  is  asbestos  ; 
which  is  pulverized  and  iised  as  fire-proof  paint,  and  woven  into 
felt  for  roofing,  etc. 

Syenite  is  hornblendic  granite  ;  it  has  the  same  feldspar  and 
quartz  as  granite,  but  has  hornblende  instead  of  mica ;  it  re- 
sembles the  mica  granites  very  closely,  but  does  not  split  well. 

Granite  consists  of  feldspar,  quartz  and  mica :  it  is  the  most 
granular  of  all  rocks.  The  quartz  is  usually  white  and  glassy. 
Feldspar  is  light  red  or  yellowish  white,  and  the  mica  is  in  little 
packages  or  sheets  of  any  color  to  black.  Immense  quarries  of 
all  shades  of  granite  are  found  throughout  Maryland,  also  in 
Virginia,  New  Hampshire,  Massachusetts,  and  in  most  of  the 
United  States.  The  Equitable  Building,  Broadway,  New  York, 
is  built  of  Concord  Granite  ;  it  is  an  excellent  stone  building. 
The  Staats  Zeitung  Building  opposite  the  City  Hall,  N.  Y.,  is 
built  of  two  kinds  of  Granite  ;  the  first  story  is  Quincy  Granite ; 
the  other  stories  are  of  Concord.  The  Western  Union  Build- 
ing, N.  Y.,  is  built  of  a  light  grey  granite  from  the  vicinity  of 
Richmond,  Va.  (the  bricks  on  the  fronts  are  from  Baltimore). 

Gneiss  is  a  form  of  stratified  granite,  obscure  and  irregular  in 
strata ;  it  is  somewhat  crystaline ;  it  is  a  metamorphic  rock,  not 
valuable  generally  for  building  purposes. 

Schists  are  rocks  composed  of  finer  materials  than  the  gneiss. 
Schists  are  stratified  ;  the  strata  generally  lays  flat.  This  is  al- 
so a  metamorphic  rock. 

Slates  are  the  finer  grained  schists.  The  clay  slate  is  the 
finest  grained  of  the  slate ;  the  talcose  slate  is  the  most  metallif- 
erous, the  mica  next,  and  the  clay  slate  next 


AND    FOUNDATION    WALLS.  49 

Marble  is  the  purest  form  of  carbonate  of  lime  (except  stalac- 
tites), and  is  an  earlier  formation  of  limestone,  with  a  pressure 
which  retained  the  carbonic  acid.  The  Marble  residence  erect- 
ed for  A.  T.  Stewart,  in  New  York,  is  built  of  selected  White 
Marble  from  the  Westchester  County  quarries  of  N.  Y.  The 
Mutual  Life  Insurance  Company  Building,  of  Boston,  Mass.,  is 
built  of  Marble  from  the  quarries  of  Westchester  County,  N.  Y. 
The  Drexel  Building  is  built  of  Connecticut  Marble. 

Calcite,  or  Carbonate  of  Lime  consists  of  transparent  crystals 
when  pure,  but  changes  color  with  impurities,  becoming  white 
marble,  or  blue,  yellow  or  grey  limestones. 

Gypsum  or  Sulphate  of  Lime,  i.  e.,  the  result  of  the  action  of 
the  oxide  of  sulphur  on  oxide  of  calcium,  is  known  as  Plaster 
of  Paris. 

Oxide  of  Iron  is  a  rock-building  mineral,  and  is  diffused 
through  nearly  all  rocks  ;  makes  great  rock  masses  by  itself ; 
oxide  of  iron  in  limestone  or  sandstone  injures  it  for  dressed 
stone  surfaces. 

Talc  is  a  silicate  of  magnesia  with  some  potash  and  iron, 
greasy  of  touch ;  allied  species  are  soapstone  and  serpentine. 

Serpentine  is  a  greenish  melted  rock  ;  it  is  almost  entirely 
made  of  talc.  Some  varieties  are  used  for  fine  masonry. 

Green  Stone  is  composed  of  feldspar  and  hornblende ;  it  is 
granular  and  very  tough  and  hard  ;  it  is  the  metamorphic  form 
of  the  igneous  rock,  diorite. 

Diorite  is  hornblende  and  feldspar ;  is  grayish  white  some- 
times with  speckles  of  dark  green  spots. 

Basalt  consists  of  feldspar,  augite  and  chrysolite,  and  often 
with  iron  in  small  proportions  ;  it  is  dark  grey  or  green  to  black. 
A  basalt  stone  of  dark  color  is  extensively  quarried  in  New 
Jersey  for  rough  walls  and  foundations. 

Dolerite  is  basalt  with  chrysolite  left  out,  and  is  not  so  often, 
green  like  basalt. 

White  Trap  is  a  pure  feldspar ;  white  trap  is  used  extensively 
in  New  York  for  paving  stones. 

Sandstone.  A  Rock  composed  of  sand  agglutinated.  Com- 
pact sandstones  are  used,  for  fronts  of  buildings  ;  for  instance,. 
Bellville,  N.  J.,  brown  stone,  or  Connecticut  brown  stone,  etc.; 
Friable  Sandstone  is  not  suitable  for  constructive  purposes  ; 


5O  POWELL  S    FOUNDATIONS 

Ferruginous  sandstone ;  this  becomes  discolored  in  spots ; 
Concretionary  sandstone  ;  Micaceous  sandstone,  is  sandstone 
with  scales  of  mica:  Argillaceous  sandstone  contains  much 
clay  with  sand  ;  also  called  Shaly  stone  when  thin  and  laminated. 
Marley  sandstone  contains  carbonate  of  lime,  so  as  to  effervesce 
when  treated  with  weak  acid. 

Veins  are  the  crevices  and  fissures  of  the  rocks,  filled  with 
other  substances  than  the  rocks. 

Hydraulic  Lime  is  any  combination  of  lime  with  very  silicious 
clay. 

Marl  is  simply  limestone  ;  has  been  so  recently  formed  that 
it  has  not  yet  become  compacted  into  solid  rock. 

Pozzoulana  Tufa  is  an  earthy  rock,  not  very  hard,  made  from 
volcanic  cinder,  more  or  less  decomposed,  usually  of  a  yellowish 
brown  color  ;  it  is  used  for  hydraulic  cement. 

Sand  is  comminutive  or  pulverized  rock  of  any  kind  ;  but 
common  sand  is  mainly  quartz,  or  quartz  and  feldspar. 

Pink  and  Red  Granites — The  color  occurs  in  feldspar.  When 
used  in  buildings  they  produce  a  fine  effect,  and  can  be  highly 
polished.  Also,  when  it  is  the  intention  to  use  a  stone  without 
cutting  the  surfaces,  and  only  squared  with  a  tooled  face,  and 
where  the  edges  are  axed,  it  is  very  fine  in  effect.  Dark-red 
granite,  equal  to  the  Scotch,  is  now  quarried  in  Nova  Scotia. 

The  foregoing  list*  gives  the  average  kind  of  rocks  and  sand- 
stones of  the  earth  used  in  construction,  etc.  There  are  many 
varieties,  not  necessary  to  name  here,  with  names  peculiar  to 
the  location  of  quarries,  and  varieties  with  traces  of  metal,  etc. 

Strength  of  Building  Stone. — The  strength  of  the  building 
stone  used  in  some  parts  of  this  country  have  been  investigated 
by  crushing  tests  at  the  Columbia  School  of  Mines,  at  the  Navy 
Yard  in  Washington,  and  in  other  places. 

The  result  of  these  tests  show,  that  the  strongest  of  our  build- 
ing stones  are  the  trap  rocks  of  New  Jersey  and  Staten  Island, 
•which  bear  a  pressure  of  24,000  Ibs.,  per  cubic  inch.  They  are 
not  used,  however,  owing  to  the  cost  of  working  them,  except 
where  the  blocks  may  be  fitted  together  roughly. 

*  We  are  indebted  to  the  book  of  Mr.  F.  H.  Smith,  for  the  definition  of 
some  of  these  terms. 


AND    FOUNDATION    WALLS.  51 

The  strongest  granites  come  from  Westerly,  R.  I.,  Richmond, 
Va.,  and  Port  Deposit,  Md.  The  largest  variety  of  granites 
come  from  this  State  and  are  of  all  shades  of  grey,  green  and 
salmon  colors.  These  will  stand  a  pressure  of  17,750,  21,250  and 
1 9,750  pounds  respectively  to  the  cubic  inch.  Granite  is  the  most 
durable  of  all  stone  in  every  day  use.  The  fine  red  polished 
granites,  so  much  used  of  late,  come  from  Peterhead,  near  Aber- 
deen, Scotland,  and  the  bay  of  Fundy,  and  to  all  intents  and 
purposes  will  last  forever. 

The  strongest  marbles  come  from  Lee,  Mass.,  and  bear  13,440 
pounds  to  the  cubic  inch,  and  Tuckahoe,  N.  Y.  12,650  pounds. 
These  are  stronger  than  the  bay  of  Fundy  granite,  which  stands 
a  pressure  of  only  1 1,812  pounds  to  the  cubic  inch.  Italian  mar- 
ble will  bear  11,250  pounds,  and  the  statuary  marble  Carrara 
only  9,723  pounds  pressure  to  the  cubic  inch. 

Good  rough  marbles  are  found  in  Westchester  County.  The 
strongest  limestone  comes  from  Kingston,  N.  Y.  It  will  resist 
1 3,900  pounds  to  the  cubic  inch,  and  has  the  greatest  variety  of 
colors  of  all  building  stone. 

That  from  Glens  Falls  takes  a  high  polish  and  is  jet  black,  that 
from  Lockport  is  gray,  and  the  delicate  cream  and  dove  tints  are 
found  in  the  Athens  and  Caen  stones.  Lighter  shades  are 
found  in  the  Bermuda  and  Florida  rocks. 

The  gray  Lockport  stone  when  dressed  by  the  hammer  resem- 
bles a  light  granite,  and  is  frequently  used  for  trimming  brick 
houses.  The  cream-colored  limestone  of  Paris  basin  is  very 
soft  at  first,  and  would  be  esteemed  by  a  green  hand  unfit  for 
any  purpose,  but  it  hardens  when  dressed,  and  can  be  used  for 
the  most  delicate  work  :  the  exposure  that  would  chip  the  work 
in  other  stones  improving  it.  The  Topeka  stone  from  Kansas 
possesses  the  same  valuable  property.  When  fresh  from  the 
quarry  it  can  be  sawed  like  wood  in  any  shape.  The  lime-stones 
that  are  most  valued,  however,  in  this  country,  come  from  Dayton, 
Ohio  ;  they  are  greatly  used  by  Cincinnati  builders.  In  Chicago 
the  favorite  limestone  is  the  Athens,  before  mentioned  from 
northern  Illinois.  The  lighter  stone  comes  from  the  Ohio,  and 
belongs  to  the  lower  carboniferous.  A  medium  between  the  two, 
in  color,  comes  from  Amherst.  Both  are  excellent  for  resisting 


52  POWELL  S-  FOUNDATIONS 

fire.     Many  of  the  finest  buildings  in  Cincinnati  are  built  of  the 
Waverly  sandstone  of  a  light  dove  color. 

Another  rich  stone  is  the  St.  Genevieve  from  Missouri,  it  is 
straw  colored  and  finely  grained.  All  these  stones  will  stand  a 
greater  pressure  than  is  ever  demanded  of  them,  50,000  pounds  to 
the  sq.  ft.,  being,  perhaps  the  maximum.  The  pillars  of  All  Saints 
Church  at  Angiers  sustain  a  pressure  of  86,000  pounds  to  the 
square  foot,  and  the  columns  of  the  Pantheon  60,000  Ibs.  Build- 
ing stones  in  stores,  warehouses  and  office  buildings  are  often 
used  where  they  carry  an  actual  load  of  from  60,000  to  75,000  Ibs., 
per  sq.  foot.  Where  the  load  is  excessive  it  is  always  best  to  en- 
large the  piers,  or  add  brickwork  to  distribute  the  load. 

Footing  Stones.— 

Flags  or  slabs  of  stone  that  are  thin  make  poor  footings,  where, 
in  proportion  to  the  weight  of  the  superstructure,  they  are  car- 


ILLUSTRATION  16. 

ried  out  to  get  a  greater  bearing.  When  this  is  done,  the  stone 
will  often  rend,  and  become  displaced,  through  the  whole  batter, 
as  may  be  seen  in  Illustration  16. 

In  building  large  masses  of  work,  such  as  the  abutments  of 
bridges  and  the  like,  the  proportionate  increase  of  bearing  sur- 
face obtained  by  the  projections  of  the  footings  is  very  slight, 
and  there  is  a  great  risk  of  the  latter  being  broken  off  by  the 
settlement  of  the  body  of  the  work.  It  is  therefore  usual  in 
these  cases  to  give  very  little  projections  to  the  footing  courses, 
and  to  bring  up  the  work  with  a  battering  face,  or  with  a  suc- 
cession of  very  slight  set  offs.  See  Illustration  17. 

Footings  of  undressed  rubble  built  in  common  mortar  are  not 


AND   FOUNDATION    WALLS. 


53 


ILLUSTRATION  17. 

sate  ;  for  in  case  of  the  compression  of  the  mortar,  it  is  sure  to 
displace  the  superstructure. 

A  safe  way  of  using  rubble  is  to  break  it  up  tolerably  small, 
and  lay  it  in  the  trenches  without  mortar,  as  it  forms  a  hard  un- 
yielding bottom  so  long  as  it  is  prevented  from  spreading  later- 
ally by  the  pressure  of  the  ground. 

Where  the  building  is  of  small  rubble,  the  best  way  to  proceed 
is  to  lay  the  foundations  with  cement  mortar,  so  that  the  whole 
will  form  a  solid  mass.  In  this  case  the  size  and  shape  of  the 
stone  is  not  important. 

In  building  with  brick,  the  great  point  to  be  attended  to  in 
the  footing  courses  is  to  keep  the  back  joints  as  far  as  possible 
from  the  face  of  the  work ;  and  in  ordinary  cases  the  best  plan 
is  to  lay  the  footings  in  single  courses — the  outside  of  the  work 
being  laid,  all  headers  and  no  course  projecting  more  than  one- 
quarter  of  the  length  of  the  brick  above  it,  except  in  eight  or 
nine  inch  walls.  Where  more  bond  is  required  in  the  work,  the 
courses  must  be  doubled,  the  heading  course  above  and  the 
stretching  course  below.  See  Illustration  18. 


ILLUSTRATION  18. 


54 


POWELL  S    FOUNDATIONS 


Bricks  used  in  trenches  and  for  footings  should  be  the  hardest 
and  firmest  It  is  desirable  that  the  bottom  course  should  in  all 
cases  be  a  double  one. 

Proper  care  and  judgment  should  be  exercised  upon  laying  the 
footing  courses  of  any  building,  as  upon  them  depends  much  of 
the  stability  of  the  work. 

If  any  rents  or  interstices  are  left  in  the  beds  of  the  masonry 
or  if  the  materials  themselves  are  unsound  or  badly  put  togeth- 
er, such  carelessness  will  show  sooner  or  later,  and  then  there 
is  no  remedy  ;  or  if  one,  it  will  be  attended  with  great  expense. 

InTerted  Arches  used  in  the  footings  and  foundation  walls  of 
superstructures,  should  have  properly  considered  abutments  for 
them  on  both  sides.  If  used  at  the  extreme  angles  of  a  building 
(see  illustration  19),  the  effect  of  any  settlement  will  move  the 
corner  pier  from  a  plumb  or  vertical  position  to  the  dotted  line 
shown  on  figure.  The  execution  of  these  inverted  arches  should 
be  very  perfect,  as  any  settlement  in  them  has  a  bad  effect  on  the 
piers,  and  consequently  gives  opportunity  for  that  fracture  which 
their  presence  was  intended  to  obviate. 

Inverted  arches  may  be  constructed  with  facility  by  moulding 
their  backs  in  the  ground  to  be  occupied  by  them ;  and  this  may 
be  very  exactly  done  by  pressing  down  an  inverted  centering, 
removing  it,  and  smoothing  down  the  cement  or  concrete.  The 


ILLUSTRATION  19. 


AND   FOUNDATION    WALLS.  5$ 

setting  of  the  brick  or  stone  then  becomes  an  easy  matter.  Be- 
sides foundations  for  buildings,  inverted  arches  are  constantly 
used  in  constructing  sewers. 

The  parabolic  form  is  the  best  for  such  arches  ;  it  is  the  surest 
for  resisting  thrust,  and  besides  this  has  the  advantage  of  not 
having  to  be  sunk  in  the  ground  so  deep. 


ILLUSTRATION  20. 


Illustration  20  represents  the  method  of  getting  the  lines  for 
centering  for  a  curve  approaching  the  parabolic  or  elliptic,  and 
is  generally  used  where  half  circles  cannot  be  used. 


ILLUSTRATION  21. 


POWELLS   FOUNDATIONS 


It  is  sometimes  required  to  span  spaces  where  there  is  a  soft 
bottom,  when  inverted  arches  are  used.  In  cases  of  this  kind 
a  form  of  construction,  as  shown  in  illustration  21,  may  be  used. 


ILLUSTRATION  22. 
For  large  spaces  use  the  Elliptic  Arch, 

In  cases  where  the  ground  is  soft  the  expense  of  spreading 
out  solid  work  to  the  requisite  extent,  renders  it  necessary  to 
use  some  cheaper  method  for  the  footings.  Three  methods  may 
be  mentioned. 

First.  To  put  in  a  wide  footing  course  of  timber,  using  tim- 
ber that  will  sustain  heavy  shearing  strains  ;  it  is  best  to  char 
the  timber. 

Second.  To  put  down  a  layer  of  concrete,  using  one  of  the 
various  hydraulic  limes  in  its  composition.  The  concrete  should 
be  spread  over  the  footings  to  a  breadth  equal  to  the  bearing 
surface  of  the  stratum  below  the  footings. 

Third.  To  build  upon  a  layer  of  sand  or  gravelly  deposit, 
with  trenches  dug  to  receive  it,  which  pressing  against  the  sides 
as  well  as  the  bottom,  distribute  the  weight  of  the  structure  over 
a  large  resisting  surface 

Where  it  is  the  intention  to  erect  buildings  on  soft  ground, 
and  a  large  bearing  surface  can  be  obtained,  timber  may  be  used 
with  great  advantage,  provided  the  timber  can  be  prevented 
from  decaying.  Some  char  the  timber,  and  others  give  it  a  coat 
of  asphaltum.  If  the  ground  is  wet,  and  the  timber  is  good, 
•there  is  little  to  fear  ;  but  when  it  is  alternately  wet  and  dry  you 


AND   FOUNDATION    WALLS. 


57 


ILLUSTRATION  23. 

cannot  depend  on  unprepared  timber.  The  kyanizingand  creo- 
soting  process  was  used  some  fifteen  years  ago,  but  is  seldom 
used  now,  as  most  localities  have  some  method  of  their  own, 
such  as  hereinbefore  mentioned. 

The  best  method  of  using  planks  under  walls  is  to  cut  them 
in  short  lengths,  which  should  be  placed  across  the  foundations 
and  tied  by  longitudinal  plank,  laid  to  the  width  of  the  bottom 
course  of  the  walls,  and  spiked  to  the  bottom  planking.  See  Il- 
lustration 23. 

A  common  method  of  planking  foundations  is  shown  in  Illus- 
tration 24.  The  space  under  the  planking  should  be  rammed. 
After  this,  bed  the  sleepers  of  timber  in  concrete,  and  fill  the 
spaces  between  them  flush  with  concrete  to  the  top,  so  that  the 
planking  may  rest  on  a  solid  level  surface. 

This  same  method  is  used  under  basement  or  cellar  floors,  to 
prevent  rats  and  mice  from  getting  in  and  making  nests. 

Before  proceeding  further  with  footings  and  foundations,  it  is 
important  for  the  architect  and  builder  to  have  some  knowledge 


ILLUSTRATION  24. 

of  the  weight  and  material  used  in  the  superstructure  or  building 
to  be  supported  on  these  foundation  walls,  and  for  this  purpose 
we  present  the  following  tables  : 


NOTE. — Mr.  Dobson,  C.  E.,  who  has  devoted  considerable  time  and  atten- 
tion to  the  subject  of  foundations,  has  been  consulted  in  some  instances  on 
this  subject. 


58  POWELL'S  FOUNDATIONS 

TABLE  OF  WEIGHT  OF  TIMBERS,  DRY. 

Green  timber  usually  weighs  one-third  more  than  dry. 

Maple  49  pounds  to  a  cubic  foot. 

WhiteOak 51      "  " 

Southern  Yellow  Pine .....45      "  " 

Northern  Yellow  Pine 35      "  " 

WhitePine 30      "  " 

Spruce 25      "  " 

Hemlock 25      "  " 

Chestnut 41      "  " 

Cherry  42      "  " 

Ash 38      "  " 

WEIGHT  OF  BUILDING  STONES,  ETC.,  PER  CUBIC  FOOT. 

Granite  or  Limestone,  dressed 165  Ibs.  to  1  cubic  foot. 

Masonry  of  Granite,  well  scabbled,  mortar  rubble, 

one-fifth  of  mass— Mortar 154    "  "         " 

Brickwork,  mortar  included,  115    "  "         " 

Marble 168    u  "         " 

Hardened  Mortar  (1  to  4  and  1  to  9)— Sand  weighs  .  .103    "  "         " 

Serpentine  Stone 162    "  "         " 

Sand  (Sand  is  retentive  of  moisture  and  varies  greatly 

in  weight) 90  to  120    "  *' 

Water 62    "  * 

Clay(dry) 119    "  *' 

Hydraulic  Rosendale  Cement,  American 56    "  " 

Teil  Hydraulic  Lime 45    "  "         " 

Common  Loam  Earth,  slightly  moist 75    "  "         " 

Common  Loam  Earth,  slightly  moist,  and  firm  sand, 

moderately  packed 90tol02    "  «         " 

Gneiss— 166  Ibs.  cubic  foot,  loose  in  piles 98    «  «         « 

Hornblendic  Gneiss 175    "  «         " 


AND   FOUNDATION    WALLS. 


59 


CHAPTER  V. 

Arches  in  Walls. — At  the  springing  line  of  arch  to  walls  it  is 
well  to  provide  stone  skewbacks  or  corbelling,  represented  by 
Illustration  25. 


ILLUSTRATION  25. 

By  this  method  the  construction  of  the  arch  does  not  encroach, 
upon  the  piers. 


ILLUSTRATION  26. 


•6o  POWELL'S  FOUNDATIONS 

Construction  of  Arches. — In  constructing  brick  arches  it  is 
always  best  to  specify  arch  brick,  as  they  form  better  vous- 
soirs  than  the  parallel  brick,  and  do  not  have  to  depend  so  much 
on  the  cement  or  mortar.  Arches  over  piers  or  thick  walls, 
which  support  a  superstructure  or  several  stories,  should  be 
constructed  as  shown  in  illustration  26,  so  as  to  bond  the  arch 
trick. 

Chimney  Walls  and  Building  the  same.— A  broad,  deep  ane* 
substantial  foundation  is  necessary  below  the  action  of  frost, 
so  that  it  may  not  settle.  If  the  chimney  becomes  a  part  of 
the  walls,  the  footings  should  be  made  proportionately  broad  to 
sustain  the  weight  above. 

The  Chimney  should  be  straight  and  smooth,  having  no 
angles  or  jogs  if  possible.  No  woodwork  should  be  built  into 
the  chimney,  but  a  space  around  it  should  be  left  clear. 

The  walls  of  chimneys  when  built  six  inches  thick,  having 
the  bricks  set  on  edge  inside,  and  bonded  with  brick  laid  every 
four  or  five  courses,  is  nearly  as  safe  as  an  eight-inch  thick  wall. 
Where  four-inch  walls  are  used  around  flues  to  chimneys,  it  is 
always  best  to  carry  the  smoke-pipe  into  a  vitriolized  clay  pipe, 
this  pipe  to  run  ten  to  twelve  feet  above  the  smoke  hole.  An 
opening  at  the  bottom  of  all  flues  should  be  provided.  It  is 
usual  to  have  light  iron  frames  and  sheet  iron  doors,  so  that  the 
soot  may  be  removed  at  any  time. 

Chimneys  should  be  smoothly  plastered  with  mortar  mixed 
with  lime,  with  a  small  proportion  of  plaster  of  paris  or  cement. 
Some  architects  require  all  joints  in  flues  to  be  pointed. 

Proportion  for  Brick  Chimneys  — for  manufactories  using 
from  twenty  to  thirty  horse-power  engines. 

The  diameter  at  base  should  be  not  less  than  one-tenth  of 
the  height. 

The  footings  from  one  and  one-half  to  twice  the  thickness  of 
base  of  chimney  wall. 

Batter  of  chimney,  three-sixteenths  ;  three-eighths ;  or,  one- 
half  inch  to  one  foot  in  height. 

Thickness  of  brick  wall  at  top,  twelve  inches. 


AND    FOUNDATION    WALLS.  6* 

From  twenty-five  to  fifty  feet  below  top  of  chimney,  sixteen 
to  twenty  inches. 

From  fifty  to  seventy-five  feet  below  top,  twenty-four  inches 
to  two  feet  out  four  inches  thick. 

Such  a  chimney  would  average  from  six  feet  to  six  feet,  eight 
inches  square  at  base,  with  twenty  inches  to  two  feet  square 
flue. 

The  batter  of  chimneys  should  reduce  this  size  at  the  top  to- 
from  one-quarter  to  one-third  of  the  bottom  diameter  or  side  of 
square. 

From  one-sixth  to  one-eighth  of  the  heighth  of  chimney  the 
walls  should  be  perpendicular,  and  when  desired  at  starting  line 
of  batter,  use  a  belt  course  of  stone  or  brick. 

The  top  of  chimney  should  always  be  capped  with  stone  or 
iron  cap. 

All  brick  laid  on  inside  or  outside  of  flue  should  batter  evenly ; 
they  should  be  regular  in  size,  sound  and  hard-burned,  and  laid 
with  even  joints. 

It  is  sometimes  necessary  to  remove  dampness  in  chimney 
flues  by  building  a  fire  in  the  base,  with  light  fuel,  before  build- 
ing the  engine  fires. 

A  chimney  for  any  ordinary  boiler  should  be  twenty  to 
twenty-five  feet  high.  The  location  of  a  chimney  governs  the 
height ;  i.  e.,  in  the  vicinity  of  houses  it  should  not  be  less  than 
five  feet  above  their  roofs  ;  in  low-lands  it  is  necessary  to  carry 
the  top  above  the  downward  currents. 

Masons'  and  Stone-Cutters'  Tools. — The  names  given  tools  for 
this  purpose  vary  according  to  locality,  but  the  following  names 
are  common  over  the  United  States  : 

The  Face  Hammer.  The  head  has  one  flat  end,  and  one 
wedge  shaped  edge  for  roughly  shaping  stones  from  the  quarry  ^ 
the  head  is  8  inches  to  10  inches  long. 

The  Double  Face  Hammer  weighs  from  twenty  to  thirty 
pounds,  and  is  used  the  same  as  the  other,  but  for  the  roughest 
work. 

The  Pick  Hammer  is  used  for  rough  dressing  on  sandstone 
or  limestone ;  it  is  wedge  shaped  on  both  edges,  with  handle 
in  the  centre. 


€2  POWELL  S   FOUNDATIONS 

The  Axe  Hammer  has  also  two  wedge  edges  for  cutting ;  it 
is  ten  inches  long  and  four  inches  wide  on  each  edge.  It  is 
used  in  reducing  faces  and  joints  to  a  level,  and  for  axing  a 
uraft  around  the  edges  of  stone. 

The  Patent  Hammer  is  a  double-headed  tool,  and  holds  a  set 
of  wide,  thin  chisels.  The  chisels  are  held  in  position  with 
bolts  on  ends  of  head,  etc.  There  is  also  a  variety  of  tools  that 
require  only  the  use  of  one  hand  :  The  hand  hammer,  which 
weighs  from  two  to  five  pounds,  is  used  in  pointing,  drilling 
holes,  and  work  on  hard  rock  with  chisels ;  the  mallet  is  used 
where  sandstone  or  limestone  is  to  be  cut ;  the  chisels  used  are 
known  as  tooth  chisels,  splitting  chisels,  plug  chisels  for  split- 
ting rocks,  etc.  Stone  carvers  have  a  variety  of  tools,  for  which 
there  are  no  names  in  particular,  and  which  are  varied  according 
to  their  work. 

In  specifying  masonry,  whether  patent  hammered,  axed,  bush 
hammered,  etc.,  it  is  best  to  have  each  estimator  supply  a 
sample  cube  of  four  to  six  inches  of  -stone,  all  from  the  same 
stone,  and  of  the  style  of  work  proposed  to  be  done. 

Stone-Cutting.— All  stones  used  in  buildings  are  as  follows  : 
Rough  stones  that  are  used  as  they  come  from  the  quarry. 
Stones  roughly  squared  and  dressed. 
Stones  accurately  squared  and  finely  dressed. 


ILLUSTRATION  27. 
Drafted  or  Axed  Edge  and  Pointed  Quarry-faced  Ashlar. 

Quarry-faced  Stones  are  those  whose  faces  are  left  the  same 
as  they  come  from  the  quarry,  similar  to  illustrations. 

Drafted  Stones  are  those  on  which  the  face  is  surrounded 
with  a  chisel  draft,  the  inner  space  left  rough. 


AND    FOUNDATION    WALLS.  63 

Squared  Stones ;  all  stones  that  are  roughly  squared  and 
dressed  on  beds  and  joints,  and  where  the  thickness  of  joint  is 
from  one-half  to  one  inch  thick,  as  the  case  may  be. 

Cut  Stones. — This  is  for  all  stones  dressed  true  and  square,  with 
dressed  bed  and  joints  ;  the  edges  may  be  drafted  and  the  face 
left  rough  ;  bush  or  patent  hammered  work  on  some  sandstones 
seems  to  loosen  the  stone,  and  in  course  of  time  it  will  shell  off. 

Ashlar  or  broken  ashlar  masonry  may  have  its  faces  cut  with 
any  of  the  various  tools,  /.  e.y  bush  hammered,  patent  hammered, 
fine  pointed,  etc.,  or  rubbed  work  ;  it  is  always  known  as  cut 
work  unless  particularly  described.  (See  illustration  27.) 

Hubble  Footings  for  ordinary  walls  are  usually  built  as  shown 
in  figure  28,  of  rough  stone,  bedded  in  mortar  composed  of  one- 
third  well-burnt  stone  lime,  and  two-thirds  clean  sharp  sand  ;  A 
representing  the  footing. 

IZ 


ILLUSTRATION  28. — Rubble  Footings. 

Bond  Rubble. — Provide  a  sufficient  quantity  of  stones  ioi 
bonding  in  greater  lengths  than  the  size  of  the  rubble  stone, 
which  are  used  or  bedded  as  found  in  the  quarry.  All  interstices 
should  be  filled  with  small  stone  and  mortar  ;  and  at  the  height 
of  eighteen  to  twenty-four  inches  the  work  should  be  routed 
with  new  made  (mortar)  grouting  and  used  at  once. 


ILLUSTRATION  29. — Bond  Rubble. 


64 


POWELLS    FOUNDATIONS 


Random  Coursed  Stone  Work. — Figure   30    represents  neat 
faced  and  pointed  random  coursed  work ;  the  stones  to  be  ham- 


ILLUSTRATION  30. — Random  Course. 

mer  dressed  to  a  fair  surface,  or  tool  pointed  ;  with  neat  joints 
well  pointed  with  mortar. 

Regular  Faced  and  Squared  Stone  "Work.  —  This  is  usually 
built  above  ground,  for  basement  or  exterior  walls,  and  in  areas, 
and  is  finished  in  neat  and  regular  coursed  work,  no  course  more 
than  sixteen  inches  or  less  than  eight  inches,  as  the  case  may 
be ;  it  is  hammered  and  dressed  to  a  fair  surface,  and  the  joints 
are  close  and  true. 


~ 


ILLUSTRATION  31. — Quarry  Faced. 

Trimmed  and  Coursed  Ashlar  Facing. — The  faces  of  exterior 
walls  of  buildings  are  usually  trimmed  with  ashlar  facing  of  stone  ; 
the  joints  may  be  all  square  and  close,  or  have  moulded  or  cham- 
fered edges  with  horizontal  beveled  joints. 


T 


ILLUSTRATION  32. — Trimmed  and  Coursed  ashlar  facing* 


AND    FOUNDATION    WALLS.  65 

The  following  list  gives  some  of  the  stones  used  for  the  exte- 
rior of  buildings  for  facings  or  ashlar  work,  in  New  York  city  and 
surroundings. 

Dorchester,  New  Brunswick,  Green  Stone. — Iron  sometimes 
appears  on  the  surface  if  not  selected. 

Berea  Stone. — Blue  cast,  grey  ;  very  good ;  produces  fine  effect 
in  combination  with  brick. 

Wyoming  Yalley  Blue  Stone,  Penn. — Of  a  close  texture  ;  used 
in  front  ashlar,  trimmings,  etc.;  not  good  for  flags. 

Marble. — The  most  of  the  marble  used  in  New  York  comes 
from  the  quarries  of  Westch ester  County.  The  marble  for  the 
R.  C.  Cathedral  was  quarried  at  Pleasant ville,  New  York. 

Canaan  Marble,  of  Conn.,  is  used  some,  and  also 

The  White  Marble  of  Vermont. — The  fine  grained  marbles 
are  quarried  principally  in  Rutland,  Pittsford  and  Dorset  Coun- 
ties. 

Connecticut  Free  or  Brown  Stone  is  not  in  use  now  as  much 
as  formerly. 

Blue  Grey  Stone,  from  Cincinnati,  well  spoken  of. 

Blue  Stone  Flags  come  from  Hastings,  on  the  North  River. 

Granite. — The  greater  part  formerly  came  from  Concord,  New 
Hampshire,  but  now  granites  from  Massachusetts,  Maine,  Mary- 
land and  Virginia  are  coming  into  use. 


ILLUSTRATION  33. 

Figure  33  represents  the  faces  of  stone  before  being  dressed; 
A,  the  natural  face  ;  B.  bed  of  stone. 


66 


POWELL  S    FOUNDATIONS 


One  of  the  most  beautiful  building  stones  for  residences, 
churches,  etc.,  is  the  serpentine  stone  found  in  Chester  County, 
Penn.  It  is  known  to  preserve  its  freshness  of  color,  which  is  a 
pale  green,  varied,  in  some  specimens,  by  darker  shades  of  the 
same  color.  It  is  valuable  as  a  building  material,  and  affords  a 
pleasing  variation  from  the  monotonous  effect  of  rows  of  brick 
or  brown  stone  buildings. 

Openings  in  Heayy  Walls. — It  sometimes  occurs  in  building 
walls  that  an  opening  is  required  of  a  certain  height,  where  a 
semi-circular  arch  cannot  be  used,  and  yet  the  wall  has  to  sus- 
tain an  immense  load.  In  a  case  of  that  kind  it  is  best,  where 
brick  has  to  be  used,  to  make  the  construction  as  shown  by  Il- 
lustration 34.  A  represents  the  opening  below  segment  arch  ; 
B  the  tier  of  beams  to  be  supported ;  and  C  the  semi-circular 
arch  above  (filled  in)  to  sustain  the  total  load. 


T 

ILLUSTRATION  34. 

Dry  Area  of  Brick  or  Bubble. — Dry  areas  around  buildings 
are  sometimes  made  in  the  following  manner,  and  covered  with 
flat  stone,  or  arched  with  brick  or  rubble  stone  (see  illus.  35). 

The  bottom  to  have  a  descent  to  the  drain,  and  paved  with 
brick  laid  with  hot  pitch,  or  as  the  case  may  require. 


AND    FOUNDATION    WALLS. 


ILLUSTRATION  35. 

Preyention  of  Dampness  in  Cellar  Walls.— A  dry  cellar  is  one 
of  the  requisites  to  a  healthy  house.  A  moist  or  damp  cellar 
acts  as  a  constant  reservoir  of  damp,  chilly  and  impure  air, 
and  the  constant  movement  of  the  air  in  the  warmer  rooms 
above  causes  currents  of  this  air  to  rise  and  desseminate  them- 
selves through  the  inhabited  rooms  and  become  a  constant 
source  of  danger  to  the  health  of  all  occupants. 


ILLUSTRATION  36. 


68 


POWELL  S   FOUNDATIONS 


People  living  over  such  cellars  cannot  but  be  seriously  affected. 
Many  fatal  cases  of  sickness  can  be  traced  to  this  cause,  and, 
doubtless,  if  our  cellars  were  looked  after  more  carefully,  there 
would  be  less  complaint  of  malaria  and  kindred  ailments. 

It  is  the  purpose  in  this  chapter  to  give  several  methods  of 
building  cellar  walls  and  laying  cellar  bottoms  so  as  to  prevent 
the  penetration  of  dampness. 

Architects  often  specify  that  the  outside  of  the  walls  be  ce- 
mented from  the  footings  to  the  base  board  of  a  frame  house, 
or  the  base  line  of  stone  sill  course  of  a  brick  or  stone  house. 
When  it  is  not  required  to  make  a  cement  finish  above  the 
line  of  ground,  then  the  cement  is  stopped  off  four  to  six  inches 
below  the  ground. 

In  illustration  36,  the  earth  is  excavated  on  the  exterior  of 
walls  to  a  width  of  two  feet  from  wall,  and  a  depth  of  eighteen 
to  twenty  inches,  and  at  an  angle  of  ten  degrees  descent. 
When  this  is  firmly  packed,  lay  in  cement  one  or  two  courses 
of  brick  laid  flat  and  well  bedded  and  slushed  with  cement. 
Allow  it  to  thoroughly  dry  before  covering  with  earth. 

Where  this  method  interferes  with  flowers  and  grasses  up  to 
line  of  wall,  that  given  in  illustration  37  will  be  a  more  satisfac- 


'•  *  b  • 


ILLUSTRATION  37. 


tory  method.     This  illustration  represents  a  wall  coated  with 
cement  on  the  outside  or  without  any  cement.     To  clearly  ex- 


AND    FOUNDATION    WALLS.  69 

plain  the  method,  after  the  walls  have  been  built  and  cemented 
on  the  outside  (Rosendale  cement  is  good  for  the  purpose),  ex- 
cavate the  earth  on  the  outside  to  the  line  of  bottom  of  foot- 
ings, fill  with  firm  earth  to  top  of  footings,  pack  in  carefully, 
and  grade  surface  to  a  proper  descent,  of  not  less  than  half  an 
inch  to  the  foot.  It  would  be  better  to  give  it  an  inclination  of 
two  or  three  inches  to  the  foot.  Then  on  this  trench  or  surface 
lay  brick  as  shown,  slushed  with  cement,  and  on  the  brick  put  a 
coat  of  cement  not  less  than  I  1-2  inches  thick,  as  shown  by 
black  lines,  and  wait  for  it  to  dry.  Then  set  drain  tiles  of  the 
form  shown,  they  are  of  various  forms  (some  having  holes  in  the 
sides).  On  top  of  this  put  loosely  broken  stone,  say  three  or 
four  inches  in  size,  and  then  cover  the  whole  surface  with  earth, 
fill  up  and  pack  firmly.  After  a  week  or  two  fill  up  level  with 
ground  line  and  pave  or  sod.  Where  there  is  a  clay  bottom 
and  much  moisture  this  will  not  always  prevent  the  penetration 
of  dampness. 

To  overcome  this  difficulty,  prepare  the  interior  of  the  cellar 
as  shown  in  illustration  39  and  the  outside  of  cellar  walls  as 
shown  in  38,  which  will  be  found  to  operate  quite  successfully. 


ILLUSTRATION  38. 

There  are  clay  soils  sufficiently  solid  to  support  the  walls  of 
dwelling  houses  in  which  the  clay  in  wet  seasons  retains  moist- 


7<3  POWELL'S  FOUNDATIONS 

ure  that  is  not  carried  away  into  the  earth,  but  rises  and  works 
through  the  cellar  bottom,  keeping  it  almost  constantly  damp. 
This  is  a  serious  difficulty  to  overcome,  but  I  have  known  the 
method  shown  in  illustration  No.  38  to  be  carried  out  with  suc- 
cess. 

In  this  case  prepare  the  cellar  bottom  and  lay,  say  three  or 
four  inches  of  sand,  which  is  to  be  rolled  down  firm  and  even. 
Following  the  cellar  walls  all  around  make  shallow  gutters  in 
the  sand.  On  top  of  this  lay  a  coat  of  cement  I  1-2  to  2  inches 
in  thickness,  covering  the  whole  surface  of  the  cellar,  taking 
care  that  sufficient  descent  is  given  to  carry  the  water  to  the 
drain  leading  to  sewer. 

After  the  cement  is  fully  dry  give  it  a  complete  coat  of  as- 
phalt over  the  whole  surface  and  up  to  the  inside  line  of  brick 
walls,  carrying  the  asphalt  through  the  walls,  as  shown  in 
illustration  38,  up  on  the  outside  either  to  the  earth  line  or 
above  it. 

Illustration  39  gives  another  method  of  securing  a  dry  cellar 


ILLUSTRATION  39. 

Prepare  and  do  all  work  of  levelling  the  cellar  bottom  that 
may  be  required;  spread  over  this  sand  to  the  depth  of  three 
to  five  inches,  beat  down  with  rammer  or  make  it  firm  and  hard 
with  a  heavy  roller.  On  top  of  this,  cover  the  whole  surface 
I  1-2  inches  thick  with  American  or  English  cement ;  carry  it 


AND    FOUNDATION    WALLS.  71 

well  against  the  walls.  Coat  the  outside  walls  with  cement  I 
inch  thick  in  the  same  manner,  continuing  it  up  to  ground 
line.  When  this  is  dry,  cover  the  cellar  bottom  and  inside 
and  outside  walls  with  asphaltum  as  shown.  Apply  while  hot. 
Then  take  hard-burned,  good,  even  brick,  dip  them  in  asphalt, 
and  lay  a  floor  or  pavement  over  the  entire  cellar.  This  when 
properly  done,  makes  a  superior  floor  and  a  dry  cellar  bottom. 

A  good  cellar  floor.  When  the  cellar  bottom  is  not  very  damp 
and  there  is  no  moisture  after  rains,  a  bottom  may  be  prepared 
thus  :  Cover  the  surface  of  cellar  with  half  lime  and  cement 
mortar,  and  on  this  level,  sleepers  or  beams  for  flooring  ;  fill  in 
the  spaces  between  beams  with  concrete  up  to  the  top  of  beams, 
and  on  this  lay  the  flooring. 

A  very  durable  composition  for  a  cellar  bottom  may  be  made 
of  cement  and  asphalt.  Mix  them  in  a  large  pan  or  boiler  over 
a  fire,  and  when  thoroughly  mixed  and  tough,  spread  it  over  the 
surface. 

A  good  mixture  for  bedding  with  is  65  parts  asphalt,  10  parts 
coal  tar,  and  25  parts  sand.  It  must  be  used  while  hot. 

It  may  be  well  to  add  that  there  are  various  ways  of  ascer- 
taining the  amount  of  dampness  in  cellars. 

The  Hygrometer  Gauge  is  used  for  this  purpose.  The  ordi- 
nary form  of  this  instrument  consists  of  two  thermometers 
placed  side  by  side,  one  of  the  bulbs  being  covered  with  muslin 
or  similar  material,  and  the  muslin  wetted  with  water  when  an 
observation  is  to  be  made. 

When  the  cellar  is  quite  dry  the  evaporation  will  be  quite 
rapid,  so  that  the  thermometer,  whose  bulb  is  covered  with  the 
wet  muslin,  will  mark  a  much  lower  temperature  than  the  one 
with  the  dry  bulb,  but,  where  the  cellar  is  damp,  there  will  be 
but  little  evaporation,  and  consequently  little  difference  in  the 
markings  of  the  two  thermometers  so  that  the  difference  in  the 
readings  of  the  thermometers  forms  a  very  good  index  of  the 
degree  of  dampness. 

Another  instrument  acting  on  the  same  principle,  but  more 
finely  adjusted,  is  called  the  Psycrometer. 

Sylvester's  Process  for  Repelling  Moisture  from  External 
Walls. — The  proportions  are  first :  Mix  three-quarters  of  a  pound 


72  POWELL  S    FOUNDATIONS 

castile  soap  with  one  gallon  water ;  second,  mix  one-half  pound 
alum  with  four  gallons  water.  These  substances  to  be  perfectly 
dissolved.  The  walls  should  be  clean  and  dry,  and  the  temper- 
ature not  less  than  50°  Fah.  when  the  composition  is  applied. 

Put  the  soap  wash  on  when  boiling  hot  with  a  flat  brush,  and 
•do  not  work  to  a  froth.  Let  it  dry  twenty-four  hours,  or  be  per- 
fectly dry.  Then  put  on  the  alum  wash  at  about  65°  Fah.  for 
the  mixture,  it  should  dry  perfectly  before  putting  on  the  soap 
•wash ;  this  is  to  be  repeated  alternately  until  the  wall  is  imper- 
vious to  water.  The  alum  and  soap  forms  an  insoluble  com- 
ipound. 

Damp. — After  reading  an  article  with  the  heading  "Damp" 
in  a  foreign  journal  I  was  induced  to  make  the  following  memo- 
randa, to  suit  the  subject  in  this  country :  i.  e.: 

The  causes  of  dampness  in  buildings  are:  The  presence  of  water 
in  the  atmosphere  and  soil :  and  the  porosity  of  building  mate- 
rials which  absorb  it. 

Its  effects  are  well  known  and  may  be  classed  as  Disintegra- 
tion of  masonry  with  injury  to  any  interior  finish ;  paper  or  kal- 
somining. 

Decay  of  timber  and  injury  to  wooden  furniture. 

Developement  of  Saltpetre  on  walls,  and  mouldy  surfaces. 

Injury  to  the  health  of  the  inhabitants. 

"The  decay  of  timber  used  in  building  often  causes  structures 
to  become  unsafe  as  the  ends  of  all  the  timbers  may  be  laid  in  a 
damp  place  or  built  in,  and  completely  covered  with  cement  or 
lime  ;  this  causes  dry  rot  to  set  in  very  soon  and  the  timber  be- 
•comes  useless. 

Where  chestnut  or  poplar  beams  are  used,  they  decay  so  rap- 
idly if  used  in  damp  places  that  after  one  or  two  years,  there  is 
only  a  shell  left,  that  may  give  away,  when  subject  to  any  load. 

The  prevention  and  cure  of  dampness  may  be  accomplished 
by  the  employment  and  use  of  material  suitable  for  cellars  and 
other  parts  of  buildings  below  or  on  the  level  of  the  soil.  In 
some  cases  provide  drains  to  carry  away  from  the  outside  soil 
adjoining  the  cellar  walls  all  moisture,  and  again  cement  the  out- 
side walls  from  the  trenches  to  level  of  the  earth,  and  if  it  is  a 
clay  soil  and  there  is  much  moisture  put  a  thick  coat  of  hot  as- 


AND    FOUNDATION    WALLS.  73 

phaltum  on  the  cement.  If  this  cannot  be  done  outside  coat  the 
walls  with  cement  and  asphaltum  inside ;  the  same  may  be  ap- 
plied to  the  cellar  bottom. 

Where  dampness  is  absorbed  and  rises  in  the  walls  from  be- 
low at  the  cellar  bottom  it  is  best  to  provide  damp  courses,  of 
asphaltum  coated  brick,  grooved  heavy  enamelled  brick ;  sheet 
lead,  slate,  copper  or  glass  brick  and  a  course  of  asphaltum 
through  the  whole  thickness  of  walls. 

To  protect  the  outside  faces  of  walls  from  dampness,  where 
the  walls  are  below  ground  :  build  a  four  inch  brick  lining  ;  set 
off  2  inches  on  the  inside  of  the  walls.  If  not,  build  the  4-inch 
damp  course  on  the  outside  with  the  two-inch  air  space,  a  small 
space  at  the  top  must  be  left  open  to  allow  the  moisture  to  evap- 
orate. Wooden  strips  may  be  painted  with  bituminous  paint 
and  used  to  lath  on,  and  a  coat  of  plastering  put  on  the  whole 
surface.  A  coating  of  cement  and  asphaltum  may  be  used  on 
the  walls  for  the  same  purpose.  Sufficient  protection  may  be 
gained  in  some  cases  by  using  drain  tile  on  the  outside,  starting 
the  tile  from  the  wall  line  and  carrying  six  to  eight  feet  from  the 
•walls  with  a  descent  of  say  4  inches  to  the  foot. 

Hollow  Brick  Walls  and  also  hollow  bricks  are  used  extensive- 
ly now  ;  these  have  to  be  laid  in  such  a  manner  that  the  headers 
•do  not  abutt  against  any  inner  bricks,  and  the  stretchers  are 
laid  similar  to  the  flemish  bond  method  of  laying  bricks — see 
this  subject  under  the  heading  of  hollow  brick  walls. 

The  most  thoroughly  sanitary  foundation  for  a  building  is  con- 
crete :  cover  the  whole  area  that  is  to  be  covered  by  the  building, 
with  a  four-inch  layer  of  concrete  composed  of  two-thirds  brok- 
en stone  and  one-third  mortar ;  the  mortar  to  be  made  of  sand 
and  lime. 

Well  puddled  clay  is  said  to  make  a  good  bottom  for  founda- 
tions and  cellar  floors  ;  but  this  can  only  occur  in  extraordinary 
cases  and  localities. 

Puddle  clay  and  mix  it  in  heaps  with  ordinary  slacked  lime, 
and  burn  as  is  done  in  the  making  of  cement,  after  this  it  may 
be  mixed  with  a  sufficient  quantity  of  lime  and  water  to  work  it ; 
lay  this  all  over  the  whole  space  of  building  and  a  space  of  18 
inches  outside  of  the  building  lines. 


74  POWELL  S    FOUNDATIONS 

Gas  refuse  has  been  used  to  cover  the  interior  surface  of  damp 
walls  and  filling  all  the  space  on  surfaces  of  stone,  brick  and  mor- 
tar ;  but  the  offensive  odor  from  this  method  is  its  most  objec- 
tionable feature. 

Good  results  have  been  reported  from  the  use  of  a  solution 
made  of  soap  and  alum,  the  result  of  the  chemical  reaction  which 
follows  is  to  fill  the  pores  of  the  brick  or  stone  with  a  fatty  sub- 
stance-which  opposes  passage  of  water. 

Dampness  often  penetrates  or  water  finds  its  way  into  cellars 
under  window  sills  :  to  avoid  this  turn  up  one  course  of  brick 
inside  against  the  sill. 

Floors  in  Damp  Locations. — A  German  newspaper  of  1882, 
gives  a  lengthy  report  by  Herr  W.  Lang — on  various  methods 
used  to  gain  a  strong  and  durable  flooring  on  the  earth,  or  cellar 
bottom  in  a  manufactory,  that  would  be  dry  and  stand  the  wear 
of  loaded  trucks  rolled  over  its  surface.  At  first  a  layer  of  cem- 
ent on  a  concrete  floor  was  used  ;  but  the  necessity  of  washing 
the  floor,  together  with  the  wheels  cutting  the  top  surface,  soon 
completed  their  destruction.  Two  other  methods  were  tried. 
"After  laying  a  fresh  bed  of  concrete,  a  layer  consisting  of  sand 
and  cement  in  equal  parts  about  i  1-4  inches  thick  was  laid,  it 
was  well  rammed  down  and  then  smoothed  with  a  hand  iron. 

This  method  made  a  separate  shell  on  top,  the  same  as  tried  at 
first.  The  second  method  consisted  of  mixing  a  concrete  of  one 
part  of  cement,  two  parts  of  sand,  and  four  parts  of  gravel,  laying 
it  evenly  and  ramming  it  until  a  layer  of  from  3-4  of  an  inch  to  i 
1-4  inches  appeared  on  the  surface  without  any  gravel ;  this  layer 
was  then  levelled  and  smoothed  down.  This  floor  proved  to  be 
very  good  ;  in  all  cases  the  thickness  of  concrete  depends  upon 
the  solidity  of  the  bottom  that  it  is  put  upon,  if  left  to  thoroughly 
harden  it  will  resist  for  a  very  long  time  any  ordinary  pressure." 

In  this  article  is  a  long  account  of  some  secret  method 
of  preparing  a  concrete  that  would  effectually  prevent  the  action 
of  acids.  In  cases  of  this  kind  it  is  best  to  use  stone  slabs,  pack- 
ing the  joints  with  lead  or  sulphur  cement,  run  in  in  such  a  man- 
ner as  to  be  able  to  key  underneath,  as  the  action  of  acids 
on  cements  and  asphalts  very  soon  destroys  them.  One  of 
the  strongest  and  best  road  surfaces  or  floor  surfaces  that  can 


AND   FOUNDATION    WALLS.  7£ 

be  put  down  readily  is  by  a  method  used  in  Pine  Street,  New 
York,  as  follows  :  The  space  to  receive  the  floor  is  excavated 
and  cleared  of  all  refuse  and  rolled  to  the  level  surface  required 
for  the  whole  material.  On  this  broken  stone  sufficiently  large 
for  concrete  (say  stone  that  will  pass  through  a  ring  2  to  3 
inches  in  diameter),  is  laid  to  a  depth  of  6,  8,  or  12  inches,  and  the 
whole  surface  slushed  with  cement,  and  this  is  rolled  and  before 
it  is  dry,  a  coating  of  sand  is  laid  to  raise  and  make  an  even 
surface.  When  this  is  sufficiently  dry  there  is  put  on 
the  top  a  composition  composed  of  powdered  lime  stone  or 
marble  dust  as  coarse  as  sand,  and  mixed  with  an  equal  quanti- 
ty of  coarse,  sharp  sand,  this  is  heated  in  large  wrought  iron 
pans,  and  asphaltum  is  mixed  in  with  it  to  make  a  stiff  pliable- 
cement.  When  this  is  thoroughly  mixed  and  before  using,  the 
concrete  is  covered  in  a  rough,  scratched  manner  with  hot  as- 
phalt, and  then  on  this  the  composition  is  spread  from  buck- 
ets with  shovel,  etc.;  as  soon  as  it  is  in  position  it  is  rolled 
evenly.  A  sufficient  quantity  is  made  to  cover  an  area  of  say 
25  feet  square  each  time,  the  joints  are  cut  very  smooth  and 
true  and  when  connected  a  smooth  hot  trowel  like  iron  is  used 
to  weld  the  joints.  The  whole  surface  is  then  covered  with 
sand  ;  the  smoothing  iron  is  used  on  all  gutters  to  make  the  de- 
scent of  water  perfect.  The  day  after  some  of  this  was  finished,. 
I  saw  a  two-horse  wagon  loaded  with  brick  run  on  it.  The 
horses  backed,  turned,  and  the  brick  was  unloaded  without  any 
injury  to  the  surface  or  any  part  of  the  work. 

As  it  is  important  in  the  construction  of  foundations  of  all 
structures  to  be  prepared  for  various  emergencies,  the  following 
receipts  will  be  useful  in  nearly  every  case. 

Air  and  Water  Tight  Cement  for  Casks   and   Cisterns.— 

Melted  glue,  8  parts,  linseed  oil,  4  parts  ;  boiled  into  a  varnish 
with  litharge  ;  hardens  in  48  hours. 

Cement  for  External  use.— Ashes  2  parts,  clay  3  parts,  sand 
I  part ;  mix  with  a  little  oil,  very  durable. 

Cement  to  resist  Red  Heat  and  Boiling  Water — To  4  or  5 

parts  of  clay,  thoroughly  dried  and  pulverized,  add  2  parts  of 
fine  iron  filings  free  from  oxide,  i  part  of  peroxide  of  manga- 
nese, i  part  of  common  salt,  and  1-2  part  of  borax.  Mingle 


yg  POWELL'S  FOUNDATIONS 

thoroughly,  render  as  fine  as  possible,  then  reduce  to  thick 
paste  with  necessary  quantity  of  water,  mixing  well ;  use  imme- 
diately, and  apply  heat,  gradually  increasing  almost  to  a  white 
heat. 

Cement  to  Join  Sections  cf  Cast-iron  Wheels,  &c.— Make  a 
paste  of  pure  oxide  of  lead,  lithage  and  concentrated  glycerine. 
This  cement  is  unrivalled  for  fastening  stone  to  stone  or  iron  to 
iron. 

Soft  Cement  for  Steam  boilers,  Steam  pipers,  etc.— Red  or 
white  lead,  in  oil  4  parts ;  iron  borings  2  to  3  parts. 

Gas-fitter's  Cement.— Mix  together  resin  4 1-4  parts,  wax  i 
part,  and  Venetian  red  3  parts. 

Plumber's  Cement.— Black  resin  i  part,  brick  dust  2  parts; 
well  incorporated  by  melting  heat. 

Coppersmith's  Cement.— Boiled  linseed  oil  and  red  lead  mixed 
together  into  a  putty,  is  often  used  by  coppersmiths  and  engi- 
neers to  secure  joints,  the  leather  or  cloth  washers  are  smeared 
with  this  mixture  in  a  pasty  state. 

Composition  to  fill  the  Holes  in  Castings. — Mix,  one  part  borax 
in  solution  with  four  parts  dry  clay.  Another :  Pulverized 
binoxide  of  manganese,  mixed  with  a  strong  solution  of  sili- 
cate of  soda  (water-clay)  to  form  a  thick  paste. 

Cast-Iron  Cement. — Clean  borings,  or  turnings  of  cast  iron, 
1 6  parts ;  sal  ammoniac,  2  parts  ;  flour  of  sulphur,  i  part ;  mix 
them  well  together  in  a  mortar,  and  keep  them  dry.  When 
required  for  use,  take  of  the  mixture  I  part ;  clean  borings  20 
parts,  mix  thoroughly,  and  add  a  sufficient  quantity  of  water. 
A  little  grind-stone  dust  added,  improves  the  cement. 

Best  Cement  for  Aquaria.— i  part,  by  measure,  say  a  gill  of 
lithage  ;  i  gill  of  plaster  of  paris  :  i  gill  of  dry  white  sand  ; 
1-3  a  gill  of  finely  powdered  resin.  Sift  and  keep  corked  tight 
until  required  for  use,  when  it  is  to  be  made  into  a  putty  by 
mixing  in  boiled  oil  (linseed)  with  a  little  patent  drier  added. 
Never  use  it  after  it  has  been  mixed  with  the  oil  over  1 5  hours. 
This  cement  can  be  used  for  marine  as  well  as  fresh  water 
aquaria,  as  it  resists  the  action  of  salt  water.  The  tank  can  be 
used  immediately,  but  it  is  best  to  give  it  3  or  4  hours  to  dry. 


AND   FOUNDATION   WALLS. 


7T 


CHAPTER  VI. 

Front  Vaults. — An  important  part  of  the  construction  of 
store  buildings  in  our  large  cities  is  the  excavation  and  building 
of  vaults  under  the  streets,  or  under  the  sidewalk  and  area. 
See  abstract  of  Laws  in  reference  to  vaults,  chapter  iii. 

These  vaults  are  usually  lighted  by  setting  thick  glass  in  iron 
frames  over  the  area  known  as  area  patent  lights — and  the  side- 


ILLUSTRATION  40. 
walk  is  covered  with  arched  brick-work,  and  on  top  of  this  stone 
flags,  or  with  large  flags  of  stone,  resting  on  a  girder  or  bear 
supported  by  columns  where  necessary.     The  best  stone  11 
here  is  the  North  River  blue-stone  and  is  generally  used  t 


POWELL'S  FOUNDATIONS 


ILLUSTRATION  41. 

inches  thick.  Where  granite  has  been  used  for  the  purpose  it  has 
worn  so  smooth  as  to  become  objectionable.  The  joints  of  the 
stone  are  caulked  with  oakum,  and  filled  with  pitch  and  cement. 
See  illustration  40. 

The  top  of  walls  are  usually  coated  with  asphalt  cement.  The 
outside  retaining  wall  is  usually  two  feet  six  inches  to  three 
feet  thick,  with  a  hollow  space  of  two  or  three  inches,  and  an  in- 
side eight-inch  wall. 

Illustration  41  represents  the  construction  of  an  area  where 
the  walls  and  vault  are  extended  out  under  the  street  beyond 
the  curb.  For  this  arrangement  there  is  generally  required  a 
special  permit. 

Vaults  under  sidewalks  are  sometimes  carried  to  the  depth  of 
twenty-five  feet  below  line  of  curb,  and  make  two  stories  extend- 
ing under  sidewalk ;  the  outside  retaining  wall  is  usually  of  stone. 

Retaining  Walls. — The  nature  of  retaining  walls  when  used 
in  connection  with  buildings  can  be  more  readily  decided  upon 
than  of  revertment  and  abutment  walls  used  in  engineering  prac- 
tice. One  of  the  great  obstacles  to  overcome  in  retaining  walls 


AND    FOUNDATION    WALLS.  79 

usect  for  area  walls  around  structures,  is  to  prevent  the  water 
that  penetrates  through  the  soil  and  reaches  the  wall  from  freez- 
ing, and  forcing  the  wall  outward.  To  avoid  this  :  when  the 
wall  is  built  finish  the  top  with  a  flat  course  under  the  coping  or 
capstone,  and  cover  this  with  a  coat  of  melted  asphaltum,  and 
carry  this  asphaltum  down  to  the  bottom  of  the  footing  courses 
on  the  outside. 

The  following  table  of  slopes  is  given  as  a  guide  in  providing 
retaining  walls  at  the  base,  and  to  form  a  correct  idea  of  the 
force  of  the  soil  or  earth  thrusting  against  the  retaining  wall. 

Slopes. — (A  slope  is  an  inclined  bank  of  earth  on  the  sides  of 
any  kind  of  cutting  or  embankment. 

The  various  Angles  are  according  to  the  nature  of  the  soil 
and  the  height  of  the  slope. 

The  allowance  is  about  as  follows  : — 

TABLE  OF  SLOPES. 

•Gravel,  sand,  or  common  earth  cuts  or  banks  of  less 

than  4  feet,  1  Base  to  (1)  Vertical. 

€lay  cuts  or  banks  of  less  than  4  feet,  2  Base  to  (1)       " 
Earth  of  mixed  sand  or  clay  or  banks  of  4  to  15  feet,  1 1-2  Base  (1)       " 

Pure  gravel  or  sand  or  banks  of  4  to  15  feet,  2  Base  (1)       " 

Clay  in  banks  of  4  to  15  feet,  2    "     (1) 

Statified  clay  and  sand  cuttings  4  to  15  feet,  3  Base  to  (1)       " 

Broken  rocks  in  banks  over  15  feet  high,  1 1-2   "     "  (1)       " 

Earth  of  mixed  sand  and  clay  or  banks  over  15 

feet  high,  2     «     "(1) 

Pure  gravel  or  sand  cuts  over  15  feet  high,  "  (1) 

€lay  cuts  or  banks  over  15  feet  high,  3            "  (1) 

Statified  clay  in  cuttings  over  15  feet  high,  3  to  4           "  (1) 

The  natural  strongest,  and  ultimate  form  of  a  slope  is  a  curve, 
and  the  flattest  part  is  at  the  bottom.  When  the. slopes  remain 
without  retaining  walls,  cultivation,  sodding  and  drainage  are 
preservatives. 

The  average  angle  to  revertment  or  retaining  walls  is  as  fol- 
lows : 

1-4  Horizontal  to  1  perpendicular. 
1-2 
3-4 
1 

11-2 
13-4 
2 


go  POWELL'S  FOUNDATIONS 

The  average  thickness  of  Area  or  Retaining  walls  as  given  in 
Mr.  Trautwine's  work. 

"For  walls  of  cut  stone  or  first-class  large  range  rubble  laid 
in  mortar,  is  35  per  cent,  of  height  for  width  of  base. 

For  walls  of  good  common  scabbled  mortar  rubble  or  brick, 
40  pr.  ct.  of  height  for  width  of  base. 

For  walls  of  well  scabbled  dry  rubble,  50  pr.  ct.  of  height  for 
width  of  base. 

When  the  walls  are  not  sufficiently  thick  to  sustain  the  shear- 
ing force  they  will  bulge,  and  very  soon  the  rain  and  frost 
acting  on  them  will  seriously  damage  them,  and  will  cost  more 
to  repair  than  the  original  expense  of  walls  of  sufficient  thick- 
ness properly  bonded. 

When  retaining  walls  have  been  built,  and  where  it  is  possible  ; 
horizontal  layers  of  soil  should  be  packed  in  behind  the  walls ; 
this  will  relieve  the  force  of  material  from  pressing  against  the 
walls. 

In  cases  of  this  kind  and  where  good  stones  are  used  and  laid 
in  cement,  1-8  of  the  height  of  wall  may  be  used  for  thickness  at 
the  base,  and  if  hard  burned  full  size  bricks  are  laid  in  cement, 
i-io  of  the  height  of  walls  may  be  used  for  thickness  at  the  base, 
to  this  may  be  added  a  2-inch  air  space  to  carry  off  dampness, 
with  tent  holes  at  the  top  and  an  inner  8-inch  wall  secured  with 
iron  straps.  Where  walls  of  this  kind  are  built  longer  than 
25  feet,  counterforts  or  buttresses  bracing  the  retaining  wall 
.can  be  used.  Then  inside  counterforts  or  buttresses  should  be 
built  at  regular  intervals. 

Slate  is  now  used  very  extensively  in  our  large  cities  for  plat- 
forms and  steps  where  stone  had  been  formerly  in  use ;  instead 
of  stone  it  is  often  used  for  Sidewalk  flagging,  Bond  stones,  Cop- 
ing stones,  Sills,  Lintels,  and  floors  of  Lavatories,  Urinal  Rooms 
and  Kitchens.  As  it  is  sawed  and  planed  it  can  be  laid  with 
great  regularity,  and  various  quarries  now  furnish  it  in  even 
colored  slabs,  so  that  when  used  in  broad  surfaces  it  makes  a 
complete  finish. 

When  tested  with  blue  stone  it  is  found  sufficiently  strong  for 
most  of  building  purposes,  flagging  particularly. 


AND   FOUNDATION   WALLS. 


81 


Blue  Stone, 

It  U 

Slate, 


Length. 

15.90 
15.80 
15.80 
15.80 


TEST. 

Breadth.  Dtpth. 

11".75  1.98 
11.90  3.85 
11.75  1.97 
3".80 


11  3-4  In. 
11  3-4 
11  £4 
113-4 


8,300  Ibs. 
29.0501bs. 


. 
17.000 


hi  this  case  the  load  was  placed  in  the  centre. 

The  ultimate  strength  of  Blue  stone  and  Slate  is  (compression 
test)  about  25,000  Ibs.  per  sq.  inch.  They  break  into  fragments 
with  the  same  load. 

Slabs  of  6  feet  by  12  feet  by  3  inches  thick  are  readily  made 
square  and  true. 

TABLE   OF   STRENGTH   OF   STONE   FOR  VAULTS,  PLATFORMS,   GAL- 
LERIES,   BAY-WINDOWS   AND   OTHER   PURPOSES. 

Transverse  Strength  of  Flagging.-  W,  width  of  stone  in  inches  ; 
T,  thickness  of  stone  in  inches ;  D,  distance  between  bearing  in 
inches. 

The  Breaking  Load  in  Tons  of  2000  Ibs.  for  a  Load  on 
the  Centre  of  Surface. 

Quincy  Granite C22 

Black  Granite 430 

WxT3  Blue  Stone  Flagging 744 

•*•      J  Belleville,  New  Jersey,  Freestone 312 

Dorchester  Free   Stone 264 

Caen 144 

Ambigny 216 

Thus  a  blue  stone  flag,  100  inches  wide,  6  inches  thick,  rest- 
ing on  a  bearing,  or  on  beams,  72  inches  to  centres,  would  be 
broken  by  a  load  resting  midway  between  the  beams  or  support 

100  x  62 

x  .744=37.20  tons,  breaking  load. 

TABLE   OF   EXPERIMENTS   ON   BRICK. 


BRICKS. 

Fractured 
in  Ibs. 

Crushed 
in  I'..*. 

Fractured 
sq.  in. 

Crushed 
sq.  in. 

20,000 
12,000 
20,000 
15,000 
20,000 
50.000 
40,000 

46,000 
30,000 
50,000 
60,000 
54,000 
not  crushed 
60,000 
20,000 
15,000 
55,000 
60,000 

625 
375 
625 
468 
625 
1562 
1250 

*406 
2375 

!«.-> 
835 

1875 
3375 

1875 
625 
468 
3437 

u             tt 

Dry  Pressed  Staten  Island  

Philadelphia  (whole)  

«           Oialf^ 

13,000 
38,000 

Best  Hard  North  River  Pavers  (half) 
NorthRiver  wholeBrick  not  injured  at 

Adamantine  Press  Cis-brick,  crushed  at  90,000  Ibs,  being  at  the  rate  of  2,800 
Ibs.  on  the  square  inch. 


g2  POWELL'S  FOUNDATIONS 

It  is  best  in  using  these  tables  not  to  exceed  a  working  load 
of  one-quarter  to  one-sixth  the  breaking  load.  Over  vaults  to 
warehouses  allow  a  load  of  600  pounds  per  square  foot,  and  500 
pounds  per  square  foot  for  stores. 

RULES   OR   TABLE   FOR   CALCULATING   THE   WEIGHT   OF    MATE- 

RIALS   IN    BUILDINGS. 

Calculate  the  weight  of  wall  per  superficial  foot  of  surface,  and  deduct 
only  one-half  of  window  openings. 

8-inch  brick  wall,  weight  per  foot  ....................    77  pounds. 

19       U  U  «  4?  44          44         ......     .............  115  " 

«     « 


153 


Brown  Stone,  4  inches  thick  ...........................  67 

u  44      g      44         "     ...........................  114       " 

u  44     12      "          "     ...........................  170       " 

Granite,  per  foot  ......................................  1  66       " 

White  Marble  ................................   ........  168 

NEW   YORK   LAW    IN    REFERENCE    TO   LOAD   ON   FLOORS. 
Hardware  Store,  weight  on  square  foot  floor  surface  .........  350  to  600  Ibs. 


.350 

"       310 

"       180 

"       100 

"       90 


Flour  Store, 
Dry  Goods  Store, 
Public  Assemblies, 
Tenement  House, 
Roofs, 

After  making  calculations  of  loads  in  ten  dry  goods  stores, 
they  were  found  not  to  be  loaded  to  exceed  180  pounds  per 
square  foot  on  the  basement  or  first  and  second  stories,  and  much 
less  above. 

Mensuration  of  Superfices.—  Simple  rules  for  calculating  super- 
ficial surfaces  of  different  shapes  : 

Triangle  —  Multiply  base  by  perpendicular  and  divide  by  2. 

Equilateral  Triangle  —  Square  of  any  side  by  .433. 

Trapezoid  —  Multiply  the  sum  of  the  parallel  sides  by  perpen- 
dicular distance  between  them  ;  divide  by  2. 

Parallelogram  —  Multiply  base  by  perpendicular. 

Trapezium  —  Multiply  diagonal  by  one-half  sum  of  perpendic- 
ular circle. 

Circle  —  Multiply  diameter  2  by  .7854. 

Circle  —  Multiply  circumference  by  radius,  divided  by  2. 

Ellipse  —  Multiply  transverse  axis  by  conjugate  axis  by  .7854. 

Cylinder  —  Multiply  length  by  diameter  by  3  1-7. 


AND    FOUNDATION    WALLS.  g* 

Hollow  Walls  for  Buildings.— 

There  has  not  been  so  great  a  demand  for  hollow  walls  in 
building  during  the  past  eight  years  in  cities  as  formerly,  owing 
to  the  introduction  and  manufacture  of  various  kinds  of  hollow, 
cellular  and  grooved  ;  fire-proof  and  furring  material :  most  of 
these  are  made  of  cinders,  ashes  and  clay,  mixed  with  some 
form  of  Carbonate  of  lime  or  cement ;  and  some  of  which  are 
worthless. 

For  walls  that  have  been  exposed  on  the  exterior  to  weather 
and  where  there  is  a  tendency  for  moisture  to  drive  through, 
fire-proofing  blocks  of  2  inches  in  thickness  are  set  against  the 
inside  of  walls,  these  blocks  are  grooved  on  the  side  next  to  the 
walls,  and  leave  an  air  space  :  where  they  are  not  used  wooden 
strips  are  often  used  and  the  strips  lathed.  One  reason  why 
hollow  walls  are  not  built  is,  the  Building  Laws  require  as  many 
brick  to  a  hollow  wall  per  foot  in  height  as  if  it  were  solid, 
and  as  it  is  more  expensive,  there  is  not  much  gained  in  city 
buildings  by  using  them. 

Where  stone  walls  are  built  to  have  an  air  space,  it  is  usually 
done  by  leaving  a  space  of  2  inches  on  the  inside  of  wall  of 
building,  and  building  a  4  or  8-inch  brick  wall  which  is  held  in 
position  with  wedge  anchors.     If  convenient,  fireproof  furring 
may  be  used.     This  furring  of  walls  adds  greatly  to  the  warmth 
of  a  building.     It  may  be.  useful  to  give  the  relative  conducting 
power  of  different  building  materials,  /.  e.;  as  follows  : 
Stone  14  to  1 6, 
Brick  5, 
Plaster  4, 
Wood  i, 

Wood  therefore  is  the  best  material  named :  particularly  when 
double  furring  or  woolen  felting  is  used. 

We  herewith  give  illustrations  42  and  43  showing  several 
methods  of  building  Hollow  Walls  where  no  extra  furring  will  be 
required  inside  to  prevent  the  penetration  of  dampness. 

One  of  the  greatest  protections  to  walls  above  ground  where 
hollow  walls  have  not  been  used  is  to  give  the  whole  surface  2 
heavy  coats  of  boiled  linseed  oil :  there  are  also  other  methods 
such  as  silicate  of  soda  paint  and  cement  paints — while  hollow 


84 


POWELL'S  FOUNDATIONS 


brick  walls  make  a  dry  and  damp-proof  structure :  the  work  is 
required  to  be  done  by  skilled  workmen  and  the  joints  laid  clean, 
to  leave  the  air  spaces  free. 


e    £*- 


ILLUSTRATION  42. 


AND   FOUNDATION   WALLS. 


-> 

ir 

.—  y 

ir 

1 

I 

f 

r 

-I 

! 

\ 

en 

2 

1 

0 

^ 

7 

— 

-^v 

3 

v. 

~^, 

!! 


i 


ILLUSTRATION  48. 

A  Stono  House  properly  built  is  undoubtedly  the  most  ex- 
pensive structure  that  can  be  erected.     It  produces  a  fine,  sub- 


86  POWELL'S  FOUNDATIONS 

stantial  and  showy  external  appearance  ;  and  creeping  vines 
may  be  grown  at  inner  angles  to  produce  that  picturesque  and 
home-like  appearance'  that  is  seldom  seen  in  other  structures. 
But  such  a  house  is  not  any  warmer  in  winter,  or  cooler  in  sum- 
mer, than  a  brick  one. 

The  proper  construction  for  the  walls  of  a  stone  dwelling, 
is  to  have  the  beds  and  joints  of  squared  or  drafted  stone. 
This  is  termed  squared  random  work.  This  enables  the  mason 
to  more  fully  fill  the  joints  with  mortar. 

The  walls  of  a  stone  house  should  not  be  constructed  of 
rough  rubble-work,  as  it  is  impossible  to  fill  completely  all  the 
joints  with  mortar ;  and  hence  in  a  driving  storm  rain  will  be 
forced  through  the  crevices,  and  produce  dampness  ;  quarry-faced 
stone  at  the  least  should  be  used. 

A  stone  house  can  be  constructed  either  with  hollow  or  solid 
walls,  or  the  inside  lined  with  hollow  brick. 

When  hollow  walls  are  built,  the  outside  wall  should  be  not 
less  than  sixteen  inches  thick  of  stone,  with  a  three-inch 
space  inside,  and  backed  up  with  four  inches  of  brickwork. 
Bonding  the  inside  and  outside  walls  with  iron  ties  or  clamp 
anchors.  Where  binders  or  headers  of  brick  are  used  damp- 
ness will  usually  penetrate.  Hollow  walls  to  be  effectual,  must 
have  outside  and  inside  work  separate  from  each  other. 

When  solid  walls  are  used  they  should  be  furred  and  lathed, 
instead  of  applying  the  plaster  on  the  walls. 

BUILDING  LAWS  PASSED  APRIL,   1871. 

Abstract  from  the  Building  Laws  of  the  City  of  New  York 
in  reference  to  Walls,  Foundations,  etc.,  now  in  force. 

"SEC.  3.  Depth  of  Foundation  Walls.— All  foundation  walls 
shall  be  laid  not  less  than  four  feet  below  the  surface  of  the 
earth  on  a  good  solid  bottom,  and  in  case  the  nature  of  the 
earth  should  require  it,  a  bottom  of  driven  piles  or  laid  timbers, 
of  sufficient  size  and  thickness,  shall  be  laid  to  prevent  the 
walls  from  settling,  the  top  of  such  pile  or  timber  bottom  to  be 
driven  or  laid  below  the  water  line  ;  and  all  piers,  columns, 
posts  or  pillars  resting  on  the  earth,  shall  be  set  upon  a  bottom 


AND    FOUNDATION    WALLS.  8/ 

in  the  same  manner  as  the  foundation  walls.  Rock  bottom. 
Whenever  in  any  case  the  foundation  walls  or  walls  of  any 
building  that  may  hereafter  be  erected,  shall  be  placed  on  a  rock 
bottom,  the  said  rock  shall  be  graded  off  level  to  receive  the 
same.  All  excavations  upon  the  front  or  side  of  any  lot  ad- 
joining a  street  shall  be  properly  guarded  and  protected  by  the 
person  or  persons  having  charge  of  the  same,  so  as  to  prevent 
the  same  from  being  or  becoming  dangerous  to  life  or  limb. 
Excavations.  Whenever  there  shall  be  any  excavation,  either 
of  earth  or  rock,  hereafter  commenced  upon  any  lot  or  piece  of 
land  in  the  city  of  New  York,  and  there  shall  be  any  party  or 
other  wall  wholly  or  partly  on  adjoining  land,  and  standing  up- 
on or  near  the  boundary  line  of  said  lot,  if  the  person  or  per- 
sons, whose  duty  it  shall  be  under  existing  laws  to  preserve  and 
protect  said  wall  from  injury,  shall  neglect  or  fail  so  to  do,  after 
having  had  a  notice  of  twenty-four  hours  from  the  Department 
of  Buildings  so  to  do,  the  Superintendent  of  Buildings  may 
enter  upon  the  premises,  and  employ  such  labor  and  take  such 
steps  as  in  his  judgment  may  be  necessary  to  make  the  same 
safe  and  secure,  or  to  prevent  the  same  from  becoming  unsafe 
or  dangerous,  at  the  expense  of  the  person  or  persons  owning 
said  wall  or  building  of  which  it  may  be  a  part,  and  any  person 
or  persons  doing  the  said  work,  or  any  part  thereof,  under  and 
by  direction  of  the  said  Superintendent,  may  bring  and  main- 
tain an  action  against  the  owner  or  owners,  or  any  one  of  them, 
of  the  said  wall  or  building  of  which  it  may  be  a  part,  for  any 
work  done  or  materials  furnished  in  and  about  the  said  premises, 
in  the  same  manner  as  if  he  had  been  employed  to  do  the  said 
work  by  the  said  owner  or  owners  of  the  said  premises. 

"SEC.  4.  Base  course  of  foundation  walls,  piers,  columns,  etc. 

The  footing,  or  base  course,  under  all  foundation  walls,  and 
under  all  piers,  columns,  posts,  or  pillars  resting  on  the  earth, 
shall  be  of  stone  or  concrete  ;  and  if  under  a  foundation  wall, 
shall  be  at  least  twelve  inches  wider  than  the  bottom  width  of 
the  said  wall ;  and  if  under  piers,  columns,  posts,  or  pillars,  shall 
be  at  least  twelve  inches  wider  on  all  sides  than  the  bot- 
tom width  of  the  said  piers,  columns,  posts,  or  pillars,  and  not  less 
than  eighteen  inches  in  thickness  ;  and  if  built  of  stone,  the 


38  POWELL'S  FOUNDATIONS 

stones  thereof  shall  not  be  less  than  two  by  three  feet  and  at 
least  eight  inches  in  thickness  ;  and  all  base  stones  shall  be 
well  bedded  and  laid  edge  to  edge ;  and  if  the  walls  be  built  of 
isolated  piers,  then  there  must  be  inverted  arches,  at  least 
twelve  inches  thick,  turned  under  and  between  the  piers,  or  two 
footing  courses  of  large  stone,  at  least  ten  inches  thick  in  each 
course.  Construction  of  foundation  walls.  All  foundation 
walls  shall  be  built  of  stone  or  brick,  and  shall  be  laid  in  cement 
mortar,  and  if  constructed  of  stone,  shall  be  at  least  eight 
inches  thicker  than  the  wall  next  above  them,  to  a  depth  of  six- 
teen feet  below  the  curb  level,  and  shall  be  increased  four  inches 
in  thickness  for  every  additional  five  feet  in  depth  below  the  said 
sixteen  feet ;  and  if  built  of  brick,  shall  be  at  least  four  inches 
thicker  than  the  wall  next  above  them  to  a  depth  of  sixteen  feet 
below  the  curb  level,  and  shall  be  increased  four  inches  in  thick- 
ness for  every  additional  five  feet  in  depth  below  the  said  six- 
teen feet. 

"SEC.  5.  Height,  Thickness  and  materials  of  walls  of  dwell- 
ings. In  all  dwelling-houses  that  may  hereafter  be  erected, 
not  more  than  fifty-five  feet  in  height,  the  outside  walls  shall 
not  be  less  than  twelve  inches  thick  ;  and  if  above  fifty-five  feet 
in  height,  and  not  more  than  eighty  feet  in  height,  the  outside 
walls  shall  not  be  less  than  sixteen  inches  thick  to  the  top  of 
the  second-story  beams,  provided  the  same  is  twenty  feet  above 
the  curb  level,  and  if  not,  then  to  the  under  side  of  the  third- 
story  beams ;  and  also  provided  that  that  portion  of  the  walls 
twelve  inches  thick  shall  not  exceed  forty  feet  in  height  above 
the  said  sixteen-inch  wall.  No  party  wall  in  any  dwelling-house 
that  may  hereafter  be  erected  shall  be  less  than  sixteen  inches 
in  thickness  ;  and  in  every  dwelling-house  hereafter  erected 
more  than  eighty  feet  in  height,  four  inches  shall  be  added  to 
the  thickness  of  the  walls  for  every  fifteen  feet,  or  part  thereof, 
that  is  added  to  the  height  of  the  building. 

"SEC.  6.  Height,  thickness  and  materials  of  walls  of  build- 
ings other  than  dwellings.  In  all  buildings,  other  than  dwelling- 
houses,  hereafter  to  be  erected,  not  more  than  forty-five  feet  in 
height,  and  not  more  than  twenty-five  feet  in  width,  the  outside 
walls  shall  not  be  less  than  twelve  inches  thick,  and  the  party 


AND    FOUNDATION    WALLS. 


89 

walls  not  less  than  sixteen  inches  thick ;  if  above  forty-five  feet, 
and  not  more  than  fifty-five  feet  in  height,  the  outside  and  party 
walls  shall  not  be  less  than  sixteen  inches  thick  ;  if  above  fifty- 
five  feet,  and  not  more  than  seventy  feet  in  height,  the  outside 
and  party  walls  shall  not  be  less  than  twenty  inches  thick  to  the 
height  of  the  second-story  beams,  and  not  less  than  sixteen 
inches  thick  from  thence  to  the  top  ;  and  if  above  seventy  feet, 
and  not  more  than  eighty-five  feet  in  height,  the  outside  and 
party  walls  shall  not  be  less  than  twenty  inches  thick  to  the 
height  of  the  third -story  beams,  and  not  less  than  sixteen  inches 
from  thence  to  the  top  ;  and  if  above  eighty-five  feet  in  height, 
the  outside  and  party  walls  shall  be  increased  four  inches  in 
thickness  for  every  ten  feet  or  part  thereof  that  shall  be  added 
to  the  height  of  the  said  wall  or  walls.  Buildings  over  25  feet 
in  width  to  have  partition  walls  or  girders  and  columns.  In  all 
buildings  over  twenty-five  feet  in  width,  and  not  having  either 
brick  partition  walls  or  girders,  supported  by  columns  running 
from  front  to  rear,  the  walls  shall  be  increased  an  additional 
four  inches  in  thickness,  to  the  same  relative  thickness  in  height 
as  required  under  this  section,  for  every  additional  ten  feet  in 
width  of  said  building,  or  any  portion  thereof.  It  is  understood 
that  the  amount  of  materials  specified  may  be  used  either  in 
piers  or  buttresses,  provided  the  outside  walls  between  the  same 
shall  in  no  case  be  less  than  twelve  inches  in  thickness  to  the 
height  of  forty  feet,  and  if  over  that  height,  then  sixteen  inches 
thick ;  but  in  no  case  shall  a  party  wall  between  the  piers  or 
buttresses  of  a  building  be  less  than  sixteen  inches  in  thickness. 
Corner  buildings,  thickness  of  walls.  In  all  buildings  hereafter 
erected,  situated  on  the  street  corner,  the  bearing  wall  thereof 
(that  is,  the  wall  on  the  street  upon  which  the  beams  rest)  shall  be 
four  inches  thicker  in  all  cases  than  is  otherwise  provided  for  by 
this  act. 

"SEC.  7.    Partition  walls  of  buildings  over  30  feet  in  width. 

Every  building  hereafter  erected,  more  than  thirty  feet  in  width, 
except  churches,  theatres,  or  other  public  buildings,  shall  have 
one  or  more  brick,  stone,  or  fire-proof  partition  walls,  running 
from  front  to  rear,  which  may  be  four  inches  less  in  thickness 
than  is  called  for  by  the  clauses  and  provisions  above  set  forth 


9O  POWELL'S  FOUNDATIONS 

with  regard  to  foundations,  thickness,  and  height,  provided  they 
are  not  more  than  fifty  feet  in  height ;  these  walls  shall  be  so 
located  that  the  space  between  any  two  of  the  bearing  walls  of 
the  building  shall  not  be  over  twenty-five  feet.     Iron  or  wooden 
girders,  and  bearing  weight  of  same.    In  case  iron  or  wooden 
girders,  supported  upon  iron  or  wooden  columns,  are  substituted 
in  place  of  partition  walls,  the  building  may  be  fifty  feet  in  width 
but  not  more ;  and  if  there  should  be  substituted  iron  or  wooden 
girders,  supported  upon  iron  or  wooden  columns,  in  place  of  the 
partition  walls,  they  shall  be  made  of  sufficient  strength  to  bear 
safely  the  weight  of  two  hundred  and  fifty  pounds  for  every 
square  foot  of  floor  or  floors  that  rest  upon  them,  exclusive  of 
the  weight  of  material  employed  in  their  construction,  and  shall 
have  a  footing  course  and  foundation  wall  not  less  than  sixteen 
inches  in  thickness,  with  inverted  arches  under  and  between 
the  columns,  or  two  footing  courses  of  large  well-shaped  stone, 
laid  crosswise,  edge  to  edge,  and  at  least  ten  inches  thick  in 
each  course,  the  lower  footing  course  to  be  not  less  than  two 
feet  greater  in  area  than  the  size  of  the  column  ;  and  under  every 
column,  as  above  set  forth,  a  cap  of  cut  granite,  at  least  twelve 
inches  thick,  and  of  a  diameter  twelve  inches  greater  each  way 
than  that  of  the  column,  must  be  laid  solid  and  level  to  receive 
the  column.    Walls  to  be  braced  during  construction.    Any 
building  that  may  hereafter  be  erected  in  an  isolated  position, 
and  more  than  one  hundred  feet  in  depth,  and  which  shall  not 
be  provided  with  crosswalls,  shall  be  securely  braced,  both  inside 
and  out,  during  the  whole  time  of  its  erection,  if  it  can  be  done  ; 
but  in  case  the  same  cannot  be  so  braced  from  the  outside,  then 
it  shall  be  properly  braced  from  the  inside,  and  the  braces  shall 
be  continued  from  the  foundation  upward  to  at  least  one-third 
the  height  of  the  building  from  the  curb  level. 

"SEC.  8.  Cutting  of  wall.  No  wall  or  any  building  now 
erected,  or  hereafter  to  be  built  or  erected,  shall  be  cut  off  alto- 
gether below,  without  permission  so  to  do  having  been  obtained 
from  the  Superintendent  of  Buildings.  Temporary  supports, 
Every  temporary  support  placed  under  any  structure,  wall,  gird- 
er, or  beam,  during  the  erection,  finishing,  alteration,  or  repair- 
ing of  any  building,  or  part  thereof,  shall  be  equal  in  strength 
to  the  permanent  support  required  for  such  structure,  wall,  gird- 


AND   FOUNDATION    WALLS.  9! 

er,  or  beam.  Braces.  And  the  walls  of  every  building  shall 
be  strongly  braced  from  the  beams  of  each  story  until  the  build- 
ing is  topped  out,  and  the  roof  tier  of  beams  shall  be  strongly 
braced  to  the  beams  of  the  story  below  until  all  the  floors  in  the 
said  building  are  laid. 

"SEC.  9.  Headers.  All  stone  walls  less  than  twenty-four 
inches  thick,  shall  have  at  least  one  header  extending  through 
the  walls  in  every  three  feet  in  height  from  the  bottom  of  the 
wall,  and  in  every  four  feet  in  length ;  and  if  over  twenty-four 
inches  in  thickness,  shall  have  one  header  for  every  six  superfi- 
cial feet  on  both  sides  of  the  wall,  and  running  into  the  wall  at 
least  two  feet ;  all  headers  shall  be  at  least  eighteen  inches  in 
width  and  eight  inches  in  thickness,  and  shall  consist  of  a  good 
flat  stone  dressed  on  all  sides.  Heading  courses.  In  every 
brick  wall  every  sixth  course  of  brick  shall  be  a  heading  course, 
except  where  walls  are  faced  with  brick,  in  which  case  every 
fifth  course  shall  be  bonded  into  the  backing  by  cutting  the- 
course  of  the  faced  brick,  and  putting  in  diagonal  headers  be- 
hind the  same,  or  by  splitting  face  brick  in  half,  and  backing 
the  same  by  a  continuous  row  of  headers.  Stone  ashlar.  In 
all  walls  which  are  faced  with  thin  ashlar,  anchored  to  the  back- 
ing, or  in  which  the  ashlar  has  not  either  alternate  headers  and 
stretchers  in  each  course,  or  alternate  heading  and  stretching 
courses,  the  backing  of  brick  shall  not  be  less  than  twelve  inches 
thick,  and  all  twelve-inch  backing  shall  be  laid  up  in  cement 
mortar,  and  shall  not  be  built  to  a  greater  height  than  prescrib- 
ed for  twelve-inch  walls.  All  leading  courses  shall  be  good,  hard, 
perfect  brick.  Brick  backing.  The  backing  in  all  walls,  of 
whatever  material  it  may  be  composed,  shall  be  of  such  thick- 
ness as  to  make  the  walls,  independent  of  the  facing,  conform 
as  to  thickness  with  the  requirements  of  sections  five  and  six  of 
this  act. 

"Szc.  10.  Isolated  piers,  how  constructed.  Every  isolated 
pier  less  than  ten  superficial  feet  at  the  base,  and  all  piers  sup- 
porting a  wall  built  of  rubble  stone  or  brick,  or  under  any  iron 
beam  or  arch  girder,  or  arch  on  which  a  wall  rests,  or  lintel 
supporting  a  wall,  shall  at  intervals  of  not  less  than  thirty  inches 
in  height,  have  built  into  it  a  bond  stone  not  less  than  four 
inches  thick,  of  a  diameter  each  way  equal  to  the  diameter  of  the- 


-2  POWELL'S  FOUNDATIONS 

pier,  except  that  in  piers  on  the  street  front,  above  the  curb  the 
bond  stone  may  be  four  inches  less  than  the  pier  in  diameter ; 
and  all  piers  shall  be  built  of  good,  hard,  well-burnt  brick  and 
laid  in  cement  mortar,  and  all  bricks  used  in  piers  shall  be  of  the 
hardest  quality,  and  be  well  wet  when  laid.  Walls  and  piers 
under  girders  and  columns.  And  the  walls  and  piers  under  all 
compound,  cast-iron,  or  wooden  girders,  iron  or  other  columns, 
shall  have  a  bond  stone  at  least  four  inches  in  thickness,  and  if 
in  a  wall  at  least  two  feet  in  length,  running  through  the  wall, 
-and  if  in  a  pier,  the  full  size  of  the  thickness  thereof,  every  thir- 
ty inches  in  height  from  bottom,  whether  said  pier  is  in  the  wall 
or  not,  and  shall  have  a  cap  stone  of  cut  granite  at  least  twelve 
inches  in  thickness,  by  the  whole  size  of  the  pier,  if  in  a  pier ; 
.and  if  in  a  wall,  it  shall  be  at  least  two  feet  in  length,  by  the 
thickness  of  the  wall,  and  at  least  twelve  inches  in  thickness. 
Base  stone.  In  any  case  where  any  iron  or  other  column  rests 
on  any  wall  or  pier  built  entirely  of  stone  or  brick,  the  said  col- 
umn shall  be  set  on  a  base  stone  of  cut  granite,  not  less  than 
eight  inches  in  thickness  by  the  full  size  of  the  bearing  of  the 
pier,  if  on  a  pier,  and  if  on  a  wall  the  full  thickness  of  the  wall. 
Hollow  walls.  In  all  buildings  where  the  walls  are  built  hollow, 
the  same  amount  of  stone  or  brick  shall  be  used  in  their  construc- 
tion as  if  they  were  solid,  as  above  set  forth  ;  and  no  hollow 
walls  shall  be  built  unless  the  two  walls  forming  the  same  shall 
be  connected  by  continuous  vertical  ties  of  the  same  materials 
as  the  walls,  and  not  over  twenty-four  inches  apart.  Height  of 
walls,  how  computed.  The  height  of  all  walls  shall  be  compu- 
ted from  the  curb  level.  Swelled  or  refuse  brick,  use  of,  prohib- 
ited. No  swelled  or  refuse  brick  shall  be  allowed  in  any  wall  or 
pier ;  and  all  brick  used  in  the  construction,  alteration,  or  repair 
of  any  building,  or  part  thereof,  shall  be  good,  hard,  well-burnt 
brick.  Bricks  to  be  wet.  And  if  used  during  the  months  from 
April  to  November,  inclusive,  shall  be  well  wet  at  the  time  they 
are  laid. 

"SEC.  ii.  Mortar,  of  what  materials,  and  how  used.  The 
mortar  used  in  the  construction,  alteration,  or  repair  of  any  build- 
ing shall  be  composed  of  lime  or  cement,  mixed  with  sand,  in 
the  proportion  of  three  of  sand  to  one  of  lime,  and  two  of  sand 
to  one  of  cement  and  no  lime  and  sand  mortar  shall  be  used 


AND    FOUNDATION    WALLS.  QJ 

within  twenty-four  hours  after  being  mixed  ;  and  all  walls  or  parts 
thereof,  below  the  curb  level,  shall  be  laid  in  cement  mortar,  to 
be  composed  of  cement  and  mortar,  in  the  proportion  of  one 
of  cement  to  two  of  mortar.  No  inferior  lime  or  cement  shall 
be  used.  Sand.  And  all  sand  shall  be  clean/sharp  grit,  free 
from  loam  ;  and  all  joints  and  all  walls  shall  be  well  filled  with 
mortar. 

"SEC.  12.   Walls,  how  carried  up  and  anchored In  no  case, 

shall  the  side,  end,  or  party  wall  of  any  building  be  carried  up 
more  than  two  stories  in  advance  of  the  front  and  rear  walls. 
The  front,  rear,  side,  end,  and  party  walls  of  any  building  here- 
after to  be  erected  shall  be  anchored  to  each  other  every  six  feet 
in  their  height  by  tie  anchors,  made  of  one  and  a  quarter  inch 
by  three-eighths  of  an  inch  of  wrought  iron.  The  said  anchor 
shall  be  built  into  the  side  or  party  walls  not  less  than  sixteen 
inches,  and  into  the  front  and  rear  walls  at  least  one  half  the 
thickness  of  the  front  and  rear  walls,  so  as  to  secure  the  front  and 
rear  walls  to  the  side,  end,  or  party  walls ;  and  all  stone  used 
for  the  facing  of  any  building,  except  where  built  with  alternate 
headers  and  stretchers,  as  hereinbefore  set  forth,  shall  be  strongly 
anchored  with  iron  anchors  in  each  stone,  and  all  such  anchors 
shall  be  let  into  the  stone  at  least  one  inch.  The  side,  end,  or 
party  walls  shall  be  anchored  at  each  tier  of  beams,  at  intervals 
of  not  more  than  eight  feet  apart,  with  good,  strong,  wrought- 
iron  anchors,  one-half  inch  by  one  inch,  well  built  into  the  side 
Walls  and  well  fastened  to  the  side  of  the  beams  by  two  nails,, 
made  of  wrought  iron,  at  least  one  fourth  of  an  inch  in  diame- 
ter ;  and  where  the  beams  are  supported  by  girders,  the  ends  of 
the  beams  resting  on  the  girder  shall  be  butted  together  end  to- 
end,  and  strapped  by  wrought-iron  straps  of  the  same  size,  and 
at  the  same  distance  apart,  and,  in  the  same  beam  as  the  wall 
anchors,  and  shall  be  well  fastened." 

Preservation  of  Stone.— In  the  preservation  of  stone  we  now 
lay  down,  from  the  highest  practical  authorities,  the  condition 
upon  which  only  a  successful  issue  can  be  obtained : 

First.     The  materials  must  be  irremovable  and  imperishable. 

Second.  They  must  be  easily  absorbed  by,  and  thoroughly 
incorporated  with  the  stone. 


94  POWELL'S  FOUNDATIONS 

Third.  The  materials  must  be  free  from  color,  but  admit  of 
imperishable  coloration. 

Mr.  Frederick  Ransome's  process  seems  to  best  fill  all  the 
above  conditions,  meeting  most  thoroughly  every  possible  re- 
quirement. The  materials  used  are  as  follows  :  Dissolve  flint 
or  silicate  of  soda  and  chloride  of  calcium.  Flint  or  silex  is 
soluble  by  heat  under  pressure  in  a  solution  of  caustic  soda.  In 
this  form  it  is  soluble  silicate  of  soda.  In  this  form  it  is  to  be 
thoroughly  brushed  into  the  stone.  On  top  of  this  is  brushed 
into  the  stone  a  solution  of  chlorine,  which  unites  with  the  soda, 
forming  an  insoluble  silicate  of  lime.  The  silicate  of  lime  being 
white,  there  is  an  opportunity  of  using  metallic  tinting  solutions. 

Another  process  for  the  preservation  of  stone  or  brick  is  to 
dissolve  resin  with  turpentine,  and  when  heated,  to  add  linseed 
oil  to  form  a  paint. 

Another  mixture  is  made  from  unslacked  lime,  to  which  is 
added  while  slacking  oil  of  tallow.  When  the  slacking  is  com- 
plete, it  is  placed  in  a  vessel  with  alum  water  and  proto-sulphate 
of  iron.  After  settling,  it  is  drawn  off  and  used. 

Another  process  is  the  repeated  application  with  a  brush  of  a 
solution  of  beeswax  in  coal  tar  naphtha ;  when  the  color  of  the 
stone  is  to  be  preserved,  white  wax,  dissolved  in  refined  distilled 
camphene. 

None  of  these,  except  the  first,  seem  to  answer  any  practical 
purpose,  and  only  offer  a  temporary  protection. 

Here  is  a  mixture,  given  by  M.  Kuhlman,  that  seems  to  have 
been  used  with  success  for  thirty  years.  It  is  the  silicate  of 
potash.  Before  application  the  surface  requires  to  be  washed 
with  a  diluted  solution  of  caustic  potash  with  a  hard  brush. 
Three  applications  of  the  silicate  are  required  during  three  days. 

There  is  an  English  preparation  extensively  used  for  the  pur- 
pose of  repelling  moisture,  and  for  the  preservation  of  stone, 
brick,  plaster  and  cement.  It  is  a  liquid  or  solution  of  silica. 
It  is  also  used  in  kitchens,  cellars  and  basements  to  form  a  hard 
surface  on  the  walls,  impenetrable  to  water.  It  is  a  kind  of 
enamel,  and  is  put  up  in  barrels  and  by  the  gallon,  and  is  red, 
white,  blue,  green  and  chocolate.  It  is  applied  with  a  brush, 
and  is  very  inexpensive.  It  presents  a  surface  like  glazed  tile, 
and  is  not  affected  by  water  or  atmospheric  changes.  It  is  a 


AND    FOUNDATION   WALLS.  gj 

silicate   enameling  paint.     There   are  several   agencies  in  the 
United  States. 

Incrustations  on  Brick  Walls — A  greyish  white  substance 
often  appears  on  the  surface  of  bricks,  before  and  after  being 
laid  in  walls ;  it  proceeds  from  several  causes  :  and  since  the  dis- 
coloration is  very  unsightly,  and  if  removed,  may  return,  many 
builders  and  owners  of  buildings  have  tried  various  ways  to  get 
rid  of  this  precipitate.  It  occurs  generally  on  Philadelphia  and 
New  Jersey  bricks  for  front  facings.  It  is  not  seen  often  on 
the  Baltimore  or  North  River  bricks.  Limes  that  are  burned 
of  magnesian  limestone  produce  a  lime  with  a  mixture  of  magne- 
sia, and  when  made  into  mortar,  and  used  in  brickwork,  absorb 
sufficient  vapor  from  the  atmosphere  to  form  a  sulphate  of  mag- 
nesium or  epsom  salts.  It  finds  its  way  through  every  crevice 
and  pore  out  to  the  surface.  This  sulphate  of  magnesia  is  found 
in  a  crude  form  known  as  silicate  of  magnesia,  in  native  forms 
as  asbestos,  soapstone,  talc  and  French  chalk.  When  common 
salt  is  used  in  solution  on  brick,  it  leaves  a  white  precipitate 
when  dry.  Portland  cement  contains  but  a  small  proportion  of 
magnesia,  and  walls  built  with  it  show  but  little,  if  any,  deface- 
ment. Some  of  the  grades  of  Rosendale  cement  that  contain 
magnesia  and  soda  disfigure  the  surface  of  the  walls  when  used 
in  cement  mortar.  The  best  remedy  is  to  remove  the  incrusta- 
tion and  wash  the  fronts,  and  when  dry,  paint  the  surface.  If 
the  surface  is  painted  over  the  incrustations,  it  shows  different 
shades  of  color  when  the  paint  is  dry.  This  discoloration  of 
brick  walls  is  most  noticeable  in  dry  weather  on  parts  of  walls 
subject  to  dampness,  and  on  entire  walls  after  heavy  rains. 
North  and  East  walls  are  usually  the  heaviest  coated.  This 
white  precipitate  comes  from  both  bricks  and  mortars. 

To  avoid  this  white  defacement,  builders  should  use  limes 
free  from  magnesia,  and  cements  free  from  magnesia  and  soda. 

Avoid  using  bricks  that  are  burned  with  coal,  and  also  when 
the  dry  surface  of  the  brick  is  whiter  than  the  true  color.  When 
clays  are  to  be  used  for  making  pressed  brick  for  fronts  or  orna- 
mental purposes,  it  is  best  to  avoid  all  clays  containing  epsora 
salts  or  sulphate  of  magnesia. 

The  following  may  be  a  guide  to  finding  the  magnesia  in  clays: 


og  POWELL'S  FOUNDATIONS 

Take  some  clay ;  dry  the  clay  by  heat ;  reduce  it  to  a  fine 
powder,  and  saturate  with  sulphuric  acid.  Then  dry  and  calcine 
the  mass  at  a  red  heat,  in  order  to  convert  any  sulphate  of  iron 
(copperas)  that  may  be  present  to  a  red  oxide  ;  it  is  then  dis- 
solved in  water  and  sulphuret  of  lime  is  added,  to  separate  any 
remaining  portion  of  iron ;  then  pour  off  the  liquid  and  evapo- 
rate it,  and  the  crystals  that  form,  if  any,  are  the  sulphate  of 
magnesia.  This  should  be  done  by  a  chemist. 

Sulphuret  of  Lime  is  made  of — one  part  flower  sulphur,  two 
parts  lime,  ten  parts  water.  This  is  the  mixture  used  in  testing 
the  clay. 

Of  course,  if  the  sulphate  of  magnesia  is  found,  the  clay  is  not 
fit  for  front  or  ornamental  brick. 

Yet  it  is  possible  to  wash  some  clays  and  carry  off  the  mag- 
nesia. 

Another  method  of  analyzing  clay  is  as  follows  : 

Grind  the  clay  to  a  powder,  and  add  diluted  muriatic  acid  un- 
til it  ceases  to  effervesce  ;  heat  it  until  the  liquid  evaporates, 
the  residue  being  a  thin  paste ;  then  add  water  and  shake  it ; 
then  filter  the  mixture  and  dry  what  is  on  the  filtering  paper 
by  heating — this  gives  the  insoluble  matter  ;  if  magnesia  is  con- 
tained add  clean  water  so  long  as  any  precipitate  is  formed ; 
quickly  gather  the  precipitate,  and  wash  with  pure  water.  The 
residue  from  washing  is  the  magnesia. 

Sand. — Whatever  variety  of  sand  is  used  in  making  mortars 
or  cements,  it  should  be  granular,  hard  and  gritty,  sharp  and 
angular,  with  a  polished  surface,  and  nearly  uniform  in  size. 

Sand,  when  perfectly  fit  to  be  used  in  mortar,  will  bear  the 
test  of  being  rubbed  between  the  hands  without  soiling  them. 

Sand  is  not  increased  in  volume  by  moisture,  nor  contracted 
by  heat. 

The  finest  sand  screened  should  pass  through  a  wire  mesh 
one-thirty-second  of  an  inch  square  :  the  medium  size,  one-six- 
teenth of  an  inch  mesh. 

The  quality  of  mortar  or  cement  depends  chiefly  upon  the 
quality  of  the  sand.  The  common  practice  of  using  unclean 
sands,  or  road  drifts,  argillaceous  loams,  and  even  alluvium  or 
common  soil  cannot  be  too  speedily  abolished.  Masons  are  apt. 


AND   FOUNDATION   WALLS.  97 

to  compound  the  mortar  with  the  soil  used  from  the  foundations 
regardless  of  quality,  suitability  or  the  natural  consequences  of 
its  employment. 

Clean,  sharp  bank  sand,  free  from  loam  and  screened,  is  gen- 
erally used  in  mortars  for  buildings. 

As  calcium  or  lime  is  used  more  extensively  for  mortars  than 
anything  else,  it  may  be  very  desirable  to  give  the  various  com- 
pounds. 

Calcium  Oxide,  Quick  Lime, 

Hydrated  Calcium  Oxide,     Slacked  Lime, 

Carbonate  Lime,  Limestone, 

Crystallized  Lime,  Marble, 

Fossil  Lime,  Chalk, 

Sulphate  Lime,  Gypsum  or  Plaster  of  Pari% 

Mineral  Phosphate  Lime,       Apatite. 


ppQPERTY  OF 

j.  w     DONAHUE, 

SPRIG;  iei»>  MA««. 


98  POWELL'S  FOUNDATIONS 


CHAPTER  VII. 
On  the  preparation  of  Common  Mortar. 

The  lime,  when  perfectly  burnt  in  the  kiln,  should  be  packed 
in  casks  or  air-tight  vessels,  and  kept  free  from  all  moisture, 
and  should  be  opened  only  as  required. 

Unslacked  dry  lime  fresh  from  the  kiln  is  termed  caustic  or 
quick-lime.  After  water  is  added  to  it,  it  is  called  slacked  lime. 
The  exact  quantity  of  water  for  slacking  is  in  proportion  to  the 
quality  of  lime;  the  fat  or  rich  will  absorb  more  than  the 
poor  or  lean.  No  definite  rule  can  be  given  for  all  localities 
for  the  use  of  water.  The  average  is  twice  the  weight  of  water 
to  the  lime,  but  this  is  only  an  approximation.  It  is  important 
that  the  mortar  should  be  used  fresh. 

The  best  or  richest  limes  are  made  from  pure  carbonates  of 
lime,  which  usually  increase  to  twice  their  volume  when  slacked 
but  do  not  harden  well  in  damp  places.  Poor  limes  do  not  ex- 
pand much  in  volume ;  neither  do  poor  limes  harden  well  in 
damp  places. 

Limes  that  have  been  ground  are  usually  of  inferior  quality, 
often  mixed  with  refuse  lumps  and  air-slacked  lime. 

Mortar,  stuccoes  or  cements  prepared  from  ill-burnt  lime  con- 
tinue soft  and  dusty  for  a  long  time  after  being  made  whereas 
well-burnt  and  slacked  limes  soon  become  thoroughly  indurated. 

Rich  limes  hiss,  bubble  and  throw  off  great  heat  during  the 
process  of  slacking. 

The  purest  limes  require  the  largest  proportion  of  sand  and 
•water,  and  harden  in  less  time  than  the  common  limes. 

Various  substances  are  sometimes  added  to  mortar  to  increase 
the  tenacity,  and  they  impart  thereto  the  principles  of  hydraulic 
cement  to  a  greater  or  less  degree. 

They  chiefly  consist  of  burnt  clay,  ashes,  scoriae,  iron  scales 


AND    FOUNDATION    WALLS.  gg 

and  filings,  broken  pottery,  bricks,  tiles,  etc.  They  are  useful 
in  mixing  with  lime  or  mortar  to  increase  their  hardness,  but 
they  must  be  pure  and  reduced  to  a  fine  powder. 

Some  of  the  mason  builders  in  New  York  and  vicinity  who 
are  large  contractors,  make  building  mortar  for  brick  walls  of 
the  following  proportions  : 
One  barrel  of  lime, 
Six  barrels  of  sand — sharp  bank  sand, 
which  is  calculated  to  lay  one  thousand  bricks. 

The  average  number  of  bricks  laid  in  buildings  around  New 
York,  Brooklyn,  etc.,  for  each  man  is  one  thousand  per  day. 

For  mortars  for  this  purpose  many  kinds  of  limes  are  used 

Thomaston,  of  Maine ;  Briggs,  North  River ;  Snowflake  lime, 
of  Pleasantville,  N.  Y.,  etc.,  etc. 

The  proportion  of  one  measure  of  quick-lime,  either  in  lumps 
or  ground  (when  lumps  exceed  three  inches  each  way  they  re- 
quire to  be  broken),  and  five  measures  of  sand,  is  about  the 
average  used  for  common  mortar  by  many  masons.  However, 
architects  generally  specify  one  part  of  lime  to  three  of  sand. 

Mortar  generally  increases  in  volume  one-eighth  more  than 
the  bulk  of  loose  sand. 

In  walls  that  are  exposed  to  dampness,  no  lime  should  be 
used,  as  it  will  never  harden  properly.  Cement  should  be  used, 
or  use  burnt  clay  or  fine  brick-dust,  and  mix  it  with  the  lime, 
as  this  forms  a  kind  of  hydraulic  cement. 

Shell  lime  is  about  the  same  as  that  from  the  purest  lime-stone. 

The  average  weight  of  common  hardened  mortar  is  from  105 
to  1 1 5  pounds  per  cubic  foot. 

Common  grout  is  merely  common  mortar  made  so  thin  as  to 
flow  like  cream.  It  is  used  to  fill  the  interstices  left  in  the  mor- 
tar joints  of  masonry  or  brickwork,  and  is  perhaps  best  when  a 
little  cement  is  added. 

Mortar  should  be  applied  wetter  in  hot  than  cold  weather, 
especially  in  brick-work,  otherwise  the  water  is  too  much  absorb- 
ed by  the  brick.  To  prevent  this,  dip  each  brick  for  an  instant 
in  water  in  some  kind  of  vessel,  especially  if  dusty,  as  the  latter 
impairs  the  adhesion. 

Where  there  is  a  heavy  working  strain  brought  on  piers,  or 
parts  of  walls,  it  would  be  best  to  use  some  proportion  of  cement, 


1OO  POWELL'S  FOUNDATIONS 

as  the  tenacity  or  cohesion  in  some  mortars  is  not  to  be  relied 
upon  until  four  to  six  months  after  being  used.  This  is  only 
important  where  structures  are  heavily  loaded  or  of  considerable 

height. 

The  tenacity  of  good  mortar  is  usually  fifteen  and  one-halt 
pounds  per  square  inch,  or  one  ton  per  square  foot. 

The  crushing  load  may  be  taken  at  fifty  tons  per  square  foot 

Laying  bricks  or  building  walls  when  the  mortar  freezes  al- 
ways produces  weak  walls,  and  brings  expense  afterwards. 

Common  mortar  of  ashes  is  prepared  by  mixing  two  parts  of 
fresh  slacked  lime  with  three  parts  of  wood  ashes  and  when 
cold  to  be  well  beaten,  in  which  state  it  is  usually  kept  for  some 
time  ;  and  will  resist  alternate  moisture  and  dryness.  By  some 
it  is  considered  equal  to  some  of  the  water  cements. 

A  kind  of  cement  plaster  used  around  exterior  foundation 
walls  is  made  of  one  part  Portland  cement,  three  parts  lime, 
and  two  parts  sand,  with  water  sufficient  to  make  a  mortar.  But 
with  Rosendale  cement  a  small  proportion  of  lime,  if  any,  and 
one  part  sand  to  one  of  cement  is  the  best ;  and  even  with  this 
where  it  is  exposed  to  dampness,  it  is  best  to  coat  the  cement 
with  a  coat  of  asphaltum. 

To  Color  Mortars.* — This  may  be  done  by  the  use  of  various 
colored  sands.  There  are  yellow,  silver  and  gray  sands  to  be 
had  in  many  localities.  Colored  mica,  put  on  the  surface  of 
stucco  work  with  a  thin  mixture  of  lime-water  and  lime,  first 
wetting  the  surface,  leaves  a  durable  and  sparkling  finish.  Pul- 
verized bricks,  yellow  or  red,  may  be  used.  Pulverized  dust 
from  colored  marble,  also  basalt  dust,  are  all  durable.  Ochres 
stand  exposure  to  the  weather,  as  well  as  any  of  the  pigments. 

Where  black  has  been  used  for  pointing  the  joints  of  brick- 
work, the  mortar  requires  so  much  black  to  make  the  color  that 
the  mortar  becomes  poor  and  washes  off. 

Spanish  brown  is  a  species  of  earth  of  a  reddish-brown  color, 
which  depends  upon  the  sesqui-oxide  of  iron. 

The  best  quality  of  lamp-black  made  into  putty  and  used  for 
pointing  will  retain  its  color. 

*  There  are  now  pigments  manufactured  expressly  for  use  in  mortars  that 
are  said  to  hold  their  colors  excellently. 


AND   FOUNDATION    WALLS.  IOI 

A  dry  powder,  known  as  Spanish  brown,  added  to  cement  or 
mortar  is  considered  a  permanent  color. 

Gravel  Sidewalks  are  usually  laid  by  mixing  the  gravel  with 
the  sand  and  lime  ;  i.  e.,  Ten  bushels  of  gravel.  One  to  two 
bushels  of  sand.  Half  bushel  of  lime.  Of  course  it  is  required 
to  dig  trenches,  and  lay  down  common  concrete  or  broken 
stone,  to  bed  the  walks  on. 

To  Color  Bricks  Black. — Heat  asphaltum  to  a  fluid  state,  and 
moderately  heat  the  surface  bricks  and  dip  them  in  it. 

Another  method  is  to  make  a  hot  mixture  of  linseed  oil  and 
asphalt ;  heat  the  bricks  and  dip  them.  Tar  and  asphalt  are  al- 
so used  for  the  same  purpose.  It  is  important  that  the  bricks 
be  sufficiently  hot  and  held  in  the  mixture  long  enough  to  ab- 
sorb the  color,  to  the  depth  of  one-sixteenth  of  an  inch. 

Also,  for  Staining  Bricks  Red  or  Black. — A  process  similar  to 
staining  bricks  red  will  answer  for  staining  them  black,  by  sub- 
stituting lampblack  for  the  red  employed.  For  the  red,  melt  one 
ounce  of  glue  in  one  gallon  of  water.  Add  a  piece  of  alum  the 
size  of  an  egg,  then  one-half  pound  Venetian  red,  and  one  pound 
Spanish  brown.  Try  the  color  on  the  bricks  before  using,  and 
change  light  or  dark  with  the  red  or  brown:  For  staining  black 
use  the  same,  and  instead  of  the  alum  use  bi-chromate  of  potash. 
Use  as  soon  as  made,  and  in  dry  weather. 

Venetian  Cement. — Used  for  covering  floors,  terraces  and 
roofs  of  houses,  it  is  composed  of  plaster  of  paris,  sulphur,  rosin, 
pitch  and  spirits  of  turpentine  or  wax,  and  applied  when  hot. 

Coal  Ash  Mortar — Lime,  two  and  a  half  measures ;  sand,  two  and 
a  half;  coal  ashes,  two  and  a  half;  and  puzzolana,  one  and  a  half. 

Puzzolana  Mortar — For  lining  cisterns,  consists  of  slacked 
lime,  sixteen  parts  or  measures  ;  puzzolana,  eight ;  sand,  five 
and  a  quarter ;  beaten  glass,  four ;  and  smith's  cinders,  four. 
This  was,  with  the  other  three,  used  at  Gibraltar  in  1790. 

Dutch  Terras  Mortar.— (Terras  is  a  basaltic  mineral  found  in 
the  low  counties  of  Holland.)  This  is  formed  of  equal  parts  of 
lime  and  terras  by  measure. 

Very  fat  lime  is  incapable  of  hardening  in  water. 


IO2 


POWELL'S  FOUNDATIONS 


Lime,  a  little  hydraulic 
"     quite         '' 


1  Slakes  like  lime  when 
properly  calcined,  and 
hardens  under  water. 


Lime 

Clay 

60  per  cent. 
60       " 
40       " 

40  per  cent. 
50 

60        » 

Plastic  or  hydraulic  cement 

ti                                   U                         U 

u                      n                " 

Does  not  slake  under 
any  circumstances,  and 
hardens  under  water 
with  rapidity. 

30       " 
20       " 
10       " 

70        * 
80        l 
90        « 

Calcareous  brick  puzzolana 

it                       u                tt 

U                                (i                       " 

Does  not  slake  or  hard- 
en under  water,  unless 
mixed  with  fat  or  hy- 
draulic lime. 

TABLE. 

One  Bushel  Mortar 130  pounds. 

One       "     Sand 110tol20     " 

One       "     Lime 80     " 

One       "     Hair 8     " 

Cattle  hair  is  collected  from  tanneries.  It  is  best  of  medium 
length,  fresh  and  clean.  Vegetable  fibre  of  hair  has  been  used 
some,  but  not  extensively. 

Plastering  or  Stucco — When  buildings  are  plastered  on  the 
exterior,  or  parts  exposed  to  the  weather,  it  is  usually  called 
stucco-work  (the  same  word  stucco  is  in  use  for  inside  work). 
But  this  kind  of  finishing  rough  walls  is  not  much  in  use  in  this 
country. 

There  are  two  kinds  of  stucco  ;  those  made  of  lime,  and  those 
of  cement.  Cement  stucco  is  disagreeable  in  color,  and  only 
used  where  protection  to  the  walls  or  a  very  hard  surface  is  want- 
ed. The  cement  color  may  be  covered  with  paint,  and  when  used 
it  is  often  painted.  In  working  the  first  coat  it  may  be  well  to 
work  it  with  cement  plaster,  and  for  the  second  coat  use  equal 
parts  of  quick-lime  and  cement  with  silver  or  light  grey  colored 
sand.  Colors  mixed  with  the  stucco,  such  as  umbers  or  ochres 
get  dingy  and  very  unsightly  in  time.  Mineral  color  that  is  not 
liable  to  atmospheric  change  is  the  best. 

To  make  a  light  brown  shade,  use  silver  or  as  white  sand  as 
possible,  and  in  this  mix  pulverized  brown  stone  or  brown  sand- 
stone. The  pulverized  stone  dust  from  colored  marble  may  be 
used,  also  basalt  dust. 


AND   FOUNDATION    WALLS.  JQ* 

Pulverized  bricks,  yellow  or  red,  may  be  used  where  the  color 
is  known  to  be  permanent.  The  same  process  as  mentioned 
above  is  the  best  for  exterior  pointing,  as  most  coloring  substan- 
ces wash  off. 

An  external  stucco,  when  made  with  hydraulic  lime  of  Tiel, 
is  composed  thus  :  Lime  of  Tiel,  one  part ;  two  of  chalk,  and  two 
of  sand. 

Exterior  walls  have  to  be  prepared  for  plastering  by  wetting 
them,  and  leaving  the  joints  open  and  rough,  and  during  the 
work  care  should  be  taken  to  have  the  green  material  protected 
from  the  weather,  particularly  drying  winds  or  heat  of  the  sun. 
This  is  done  by  using  muslin  or  canvass  on  the  scaffolding. 

Exterior  plastering  or  stucco  is  usually  done  in  two  coat- 
work.  Both  coats  done  about  the  same  time— that  is,  the  first 
coat  is  done  sufficiently  long  for  it  to  have  set  in  the  joints,  and 
to  sustain  the  second  coat. 

The  plasterer  examines  his  work  to  find  any  places  where  it 
has  not  adhered — say  three  or  four  days  after  the  work  is  first 
done. 

Lime  and  cement,  equal  parts,  (thoroughly  mix  the  lime  be- 
fore compounding  with  the  cement,  sand  and  water),  mixed 
with  sand  and  water  makes  a  good  stucco. 

An  artificial  stone  stucco  which  seems  very  good,  is  made  of 
one  part  lime  or  cement  and  four  parts  sand,  to  which  after 
slacking  add  four  ounces  potash  or  soda,  dissolved  in  one  gallon 
boiling  water,  and  add  one  pound  shellac.  When  this  is  dis- 
solved mix  with  the  plaster,  and  use  at  once. 

There  are  quite  a  number  of  cements  that  do  not  stand  well 
for  stucco-work. 

Inside  Plastering — Is  done  in  a  variety  of  ways,  from  one  to 
three  coats  of  mortar  plastering  on  walls,  ceilings,  etc. 

When  one-coat  work  is  required,  the  plasterers  have  to  be 
careful  in  laying  or  nailing  the  laths  regular.  One-coat  work  is 
known  as  the  scratch  coat,  and  generally  finished  with  light 
hand-floating  to  give  an  even  finish,  to  receive  a  white  or  color 
wash  finish  if  desired.  If  it  is  the  intention  to  kalsomine  on 
one-coat  work,  a  very  good  finish  may  be  made  by  using  some 
hard-finish  on  the  hawk  (a  flat  board  to  hold  plaster  on,  held  in 


104  POWELL'S  FOUNDATIONS 

the  hand),  and  hand-float  the  surface  with  water  in  the  brush. 
Back  buildings  and  the  second  stories  and  attics  of  farm-houses 
are  often  finished  this  way.  It  is  very  important  in  putting  on 
the  first  coat,  to  press  the  mortar  firmly  between  the  laths  so 
.as  to  fill  up  the  spaces  between,  and  clinch  over  the  edge  of  the 
laths.  When  the  first  coat  is  ready  to  receive  the  second  or 
browning  coat,  the  surface,  before  being  perfectly  dry,  is 
scratched  or  pricked  up  on  the  surface  with  a  hand  rake  made 
of  laths ;  the  lines  are  generally  crossed  like  lattice-work,  but 
rough. 

The  proportion  for  the  scratch  coat  is  as  follows  :  One  part 
quick-lime,  four  parts  sand,  and  one-quarter  to  one-third  measure 
of  cattle  or  goat's  hair.  It  is  usually  put  on  from  three-eighths 
to  one-half  inch  in  thickness. 

For  Two-coat  Work  and  Finish. — The  scratch  coat  is  general- 
ly done  as  in  one-coat  work,  and  worked  on  the  surface  roughly, 
but  level  with  hand-floating.  It  is  required  to  keep  the  work 
plumb  and  true,  and  scratched  to  receive  the  second  coat, 
which  is  known  by  the  name  of  browning.  Where,  as  in  this 
case,  the  plastering  is  finished  with  two  coats,  the  second  coat 
is  usually  one-quarter  or  three-eighths  inch  thick,  and  will  make 
a  very  handsome  finish  if  done  with  three  parts  clear  grey  or  silver 
sand  ;  mixed  with  one  part  gauge  stuff  or  plaster  of  paris  putty, 
one  part  fine  stuff  or  lump  lime  slacked  into  a  paste,  and  suffi- 
cient clean  hair  to  hold  in  position  the  coat  when  set.  This 
coat  is  thoroughly  floated  and  troweled. 

Another  way  is  to  use  the  same  mortar,  known  as  coarse  stuff, 
for  the  second  coat,  but  with  less  hair,  and  before  it  is  dry  to 
float  it  thoroughly  with  hand-float,  brush,  trowel  and  water,  with 
some  gauge  stuff  and  a  little  sand,  forming  a  skim  finish.  This 
is  done  in  several  ways,  but  with  slight  variation,  the  same 
material  being  used. 

Three-coat  Work  and  Finish.— Prepare  wood  furring  by  cov- 
ering it  with  wood  or  metal  laths.  Wood  laths  should  break 
joint  every  eighteen  to  twenty  inches,  and  be  laid  about  three- 
eighths  to  one-half  inch  apart.  On  this  work  the  first  or  scratch 
coat  is  to  be  placed  on  the  wall,  and  after  it  is  thoroughly  dry, 


AND   FOUNDATION   WALLS.  IO5 

followed  by  the  second  or  browning  coat ;  and  the  third  is  gauge 
stuff  for  hard-finish.  This  is  worked  on  the  second  coat  with 
a  trowel  for  one  hand,  and  sometimes  for  two  hands  ;  and  by 
using  a  wet  brush  ;  skilled  mechanics  often  make  very  fine  sur- 
faces in  this  manner.  This  coat  is  usually  one-eighth  inch  thick, 
and  is  composed  of  fine  stuff  lime,  slacked  to  a  paste,  three 
parts  ;  plaster  of  paris,  or  gauge  stuff,  one  part.  No  more  is 
made  than  can  be  worked,  up  in  say  half  an  hour. 

Gauge  stuff  is  used  chiefly  for  mouldings  and  cornices — the 
moulds  beings  made  of  zinc  or  sheet  iron,  and  secured  to  a 
wooden  template  with  handles  to  run  the  template  with  mould- 
ings. For  this  purpose  it  is  common  to  mix  gradually  one-third 
plaster  of  paris  with  two-thirds  fine  stuff.  When  the  work  can 
be  done  rapidly,  equal  parts  may  be  used. 

Gauge  stuff  is  used  for  securing  ornaments  to  the  walls  or 
ceilings  and  plaster  decorations.  Plasterers  cast  sections  of 
ornamental  cornices  in  lengths  of  about  three  feet,  and  bring 
them  fresh  to  the  structure,  and  set  them  in  position.  By  this 
means  rooms  are  decorated  in  New  York  and  vicinity  at  about 
the  same  price  as  plain,  heavy  moulded  cornice  work  can  be  done. 
The  moulds  that  are  used  for  this  purpose  are  made  of  wax, 
rosin  and  oil,  and  are  usually  kept  for  use  by  ornamental  plas- 
terers. 

Stucco  finish  is  usually  made  of  fine  stuff  with  white  sand- 
four  parts  sand,  and  one.  part  fine  stuff.  There  are  other 
rules  for  stucco  finish. 

Less  cattle  hair  is  required  in  the  plaster  on  brick  walls  than 
on  laths,  and  usually  stone  and  brick  walls  have  but  one  strong 
wall  coat,  and  on  this  it  is  finished  with  lime  and  plaster  of  par- 
is,  as  in  the  last  coat  of  three-coat  work.  The  walls  should  be 
rough,  clean  and  dampened. 

One  hundred  yards  of  plastering  will  require  1,400  laths,  in 
calculating  as  there  is  much  waste,  and  four  and  a  half  bushels 
of  lime,  eighteen  bushels  of  sand,  nine  pounds  of  hair,  and  five 
pounds  of  nails  for  two-coat  work. 

One  hundred  yards  of  plastering  for  three-coat  work  requires 
seven  bushels  of  lime,  one  load  of  sand,  nine  pounds  of  hair,  five 
pounds  of  nails,  and  1,400  laths. 

Several  plasterers  in  New  York  and  vicinity  give  the  follow- 


106  POWELL'S  FOUNDATIONS 

ing  data  :  1,000  laths  will  cover  666  sq.  ft.  One  barrel  of  lime, 
one  cart-load  of  sand,  and  three  bushels  of  goat  hair  will  scratch 
coat  and  brown  coat  a  surface  of  twenty-five  square  yards. 

Oyster-shell  lime  is  only  used  for  scratch  coats,  owing  to  the 
salt  in  the  lime.  Wood-burned  lime  is  always  the  best.  A 
great  quantity  of  Pennsylvania  lime  is  burned  with  coal,  and  has 
to  be  sifted,  leaving  often  too  large  a  proportion  of  core,  which 
has  to  be  thrown  away.  Nearly  all  plasterers  use  the  lime  that 
will  work  the  easiest  with  least  labor,  and  use  materials  that  pay 
the  best  with  labor.  Thomaston  or  Rockland  lime  is  used  by 
plasterers  generally  in  vicinity  of  New  York.  Glenn's  Falls. 
lime  is  very  pure,  and  is  used  only  in  the  ornamental  arts. 


PLASTERING. 

1  INCH.       |    3-4  INCH.    1     1-2  INCH. 

One  bushel  Cement,  or  1.28  cubic  ft. 

1  1-8  sup.  yd.il  1-2  sq.  yd. 
21-4      "          3. 
31-4      "         141-2    " 

2  1-2  sq.  yds 
41-2    « 
63-4    " 

One     "           "         and  one  of  sand 
One     "           "           "   two         " 

One  cubic  yard  of  lime,  two  cubic  yards  of  sand  and  three 
bushels  of  hair  will  cover  seventy-five  superficial  feet  of  rough 
or  scratch  coat  on  wall,  or  seventy  yards  on  lath. 

One  bundle  of  laths  and  500  nails  will  cover  about  four  and  a 
half  yards. 

Mortar,  Plaster,  &c. 

Stone  Mortar. — Cement,  8  parts  ;  lime,  3  parts ;  sand,  3  parts. 
Mortar. — Lime  I  part ;  sharp,  clean  sand,  2  1-2  parts.  An  excess 
of  water  in  slaking  the  lime  swells  the  mortar  which  remains 
light  and  porous,  or  shrinks  in  drying ;  an  excess  of  sand  destroys 
the  cohesive  properties  of  the  mass.  Brown  Mortar. — Lime,  I 
part ;  sand  2  parts,  and  a  small  quantity  of  hair.  Brick  Mortar. 
— Cement,  3  parts ;  lime,  3  parts  ;  sand,  27  parts.  Lime  and 
sand,  and  cement  and  sand,  lessen  about  1-3  in  volume  when 
mixed  together.  Turkish  Mortar. — Powdered  brick  and  tiles, 
i  part ;  fine  sifted  lime,  2,  parts;  mix  with  water  to  a  proper  con- 
sistency. Very  useful  on  massive  or  very  solid  buildings. 
Interior  Plastering. — Coarse  Stuff. — Common  lime  mortar  as 
made  for  brick  masonry,  with  a  small  quantity  of  hair ;  or  by 
volumes,  lime  paste  (30  Ibs.  lime),  i  part ;  sand,  2  to  2  1-2  parts ; 
hair,  1-6  part.  When  full  time  for  hardening  cannot  be  allowed 


AND    FOUNDATION    WALLS. 


ID/ 


substitute  for  from  15  to  20  per  cent,  of  the  lime  an  equal  por- 
tion of  hydraulic  cement.  For  the  second  or  brown  coat  the 
proportion  of  hair  may  be  slightly  diminished.  Fine  Stuff.— 
(Lime  putty) ;  Lump  lime  slaked  to  a  paste  with  a  moderate 
volume  of  water,  and  afterwards  diluted  to  the  consistency  of 
cream,  and  then  evaporate  to  the  required  consistency  for  work- 
ing. This  is  used  as  a  slipped  coat,  and  when  mixed  with  sand 
or  plaster  of  paris,  it  is  used  for  the  finishing  coat.  Gauge  Stuff 
or  Hard  Finish  is  composed  of  3  or  4  volumes  of  fine  stuff  and 
one  volume  of  plaster  of  paris,  in  proportions  regulated  by  the  de- 
gree of  rapidity  required  in  hardening  for  cornices,  etc.,  the  pro- 
portions are  an  equal  volume  of  each,  viz.,  fine  stuff  and  plaster. 

Stucco  is  composed  of  from  3  to  4  volumes  of  white  sand  to  I 
volume  of  fine  stuff  or  lime  putty. 

Scratch  Coat. — The  first  of  3  coats  when  laid  upon  laths,  and 
is  from  1-4  to  3-8  of  an  inch  in  thickness.  One-Coat  Work. — 

Plastering  in  I  coat  without  finish  that  is  rendered  or  laid  eith- 
er on  masonry  or  laths.  Two-Coat  Work. — Plastering  in  2  coats 
is  done  either  in  a  laying  coat  and  set,  or  in  a  screed  coat  and 
set.  The  Screed  Coat  is  also  termed  a  Floated  Coat.  Laying 
the  first  coat  in  two-coat  work  is  resorted  to  in  common  work 
instead  of  screeding  when  the  finished  surface  is  not  required 
to  be  exact  to  a  straight-edge.  It  is  laid  in  a  coat  of  about  1-2 
inch  in  thickness.  The  laying  coat,  except  for  very  common 
work  should  be  hand-floated,  as  the  tenacity  and  firmness  of  the 
work  is  much  increased  thereby.  Screeds  are  strips  of  mortar 
twenty-six  to  twenty-eight  inches  in  width  and  of  the  required 
thickness  of  the  first  coat  applied  to  the  angles  of  a  room  or 
edge  of  a  wall  and  also  in  parallel  strips  at  intervals  of  three  to 
five  feet  over  the  surface  to  be  covered. 

When  these  have  become  sufficiently  hard  to  withstand  the 
pressure  of  a  straight-edge,  the  interspaces  between  the  screeds 
should  be  filled  out  flush  with  them,  so  as  to  produce  a  continu- 
ous and  straight,  even  surface. 

Slipped  Coat  is  the  smoothing  off  of  a  brown  coat  with  a  small 
quantity  of  lime  putty,  mixed  with  3  per  cent,  of  white  sand  so- 
as  to  make  a  comparatively  even  surface.  This  finish  answers 
when  the  surface  is  to  be  finished  in  distemper  or  paper. 


,108  POWELL'S  FOUNDATIONS 

Hard  Finish.-  -Fine  stuff  applied  with  a  trowel  to  the  depth 
of  about  one-third  of  an  inch. 

Cement  for  External  Use.— Ashes  2  parts ;  clay  3  parts ;  sand 
i  part ;  mix  with  a  little  oil.  Very  durable. 

Asphalt  Composition. — Mineral  pitch  one  part ;  bitumen  elev- 
en parts ;  powdered  stone  or  wood  ashes  seven  parts. 

Asphalt  Mastic  is  composed  of  nearly  pure  carbonate  of  lime 
and  about  nine  or  ten  per  cent,  of  bitumen.  When  in  a  state  of 
powder  it  is  mixed  with  seven  peT  cent,  of  bitumen  or  mineral 
pitch.  The  powdered  asphalt  is  mixed  with  the  bitumen  in  a 
melted  state  along  with  clean  gravel,  making  it  of  a  consistency 
that  will  pour  into  moulds.  The  asphalt  is  ductile,  and  has  elas- 
ticity to  enable  it  with  the  small  stones  sifted  upon  it  to  resist 
ordinary  wear.  Sun  and  rain  do  not  affect  it,  wear  and  tear  do 
not  seem  to  injure  it.  The  pedestrian  in  many  cities  in  the 
United  States  and  Canada  can  readily  detect  its  presence  on  the 
sidewalk  by  its  peculiar  yielding  to  the  foot  as  he  steps  over  it. 
It  is  also  a  most  excellent  roofing  material  when  rightly  applied. 

Asphalt  for  Walks. — Take  two  parts  very  dry  lime  rubbish, 
and  one  part  coal  ashes,  also  very  dry,  sift  all  fine,  mix  in  a  dry 
place  on  a  dry  day,  leaving  a  hole  in  the  middle  of  the  heap  as 
bricklayers  do  when  making  mortar.  Into  this  pour  boiling  hot 
coal-tar ;  mix,  and  when  as  stiff  as  mortar,  put  on  the  walk 
three  inches  thick  :  (the  ground  should  be  dry  and  beaten 
smooth)  ;  sprinkle  over  it  coarse  sand.  When  cold,  pass  a  light 
roller  over  it :  in  a  few  days  the  walk  will  be  solid  and  water 
proof. 

Mastic  Cement  for  Covering  the  Fronts  of  Houses. — Fifty 
parts  by  measure  of  clean,  dry  sand ;  fifty  of  limestone  (not 
burned)  reduced  to  grains  like  sand,  or  marble  dust,  and  ten 
parts  of  red-lead  mixed  with  as  much  boiled  linseed  oil  as  will 
make  it  slightly  moist.  The  bricks  to  receive  it  should  be  cov- 
ered with  three  coats  of  boiled  oil,  laid  on  with  a  brush  and  suf- 
iered  to  dry  before  the  mastic  is  put  on.  It  is  laid  on  with  a 
trowel  like  plaster,  but  is  not  so  moist.  It  becomes  hard  as 


AND   FOUNDATION   WALLS.  ICXv 

stone  in  a  few  months.     Care  must  be  exercised  not  to  use  too 
much  oil. 

Cement  for  Tile  Roofs.— Equal  parts  of  whiting  and  dry  sand, 
and  twenty-five  per  cent,  of  litharge,  made  to  the  consistency  of 
putty  with  linseed-oil.  It  is  not  liable  to  crack  when  cold  nor 
melt  like  coal-tar  and  asphalt,  with  the  heat  of  the  sun. 

Cement  for  the  Outside  of  Brick  Walls.— Cement  for  the 
outside  of  brick  walls  to  imitate  stone,  is  made  of  clean  sand 
ninety  parts ;  litharge  five  parts ;  plaster  of  paris  five  parts  ; 
moistened  with  boiled  linseed  oil.  The  bricks  should  receive 
two  or  three  coats  of  oil  before  the  cement  is  applied. 

Mexican  Method  of  Making  Hard  Lime  Floors.— This  method 
is  used  extensively  in  some  parts  of  Northern  Mexico,  where 
they  become  very  hard. 

"The  limestone  used  is  a  hard,  compact  blue  material  in  some 
places  sufficiently  hard  to  strike  fire  on  the  drills  used  in  quar- 
rying it.  It  often  contains  iron  pyrites  in  small  proportions  ;  this  is 
calcined  in  kilns  cut  out  of  soft  limestone.  After  calcination 
the  lime  is  removed  from  the  kilns  and  slacked  as  soon  as  cool. 
Part  of  a  lot  made  this  way  was  used  within  a  day  or  two  and 
part  remained  a  month  or  more  in  barrels.  All  the  work  made 
with  it  seemed  to  be  equally  good.  In  making  the  floors  a  layer 
of  broken  limestone,  three  or  four  inches  thick  was  first  laid 
evenly  over  the  surface  of  the  ground.  The  stone  being  about 
the  usual  size  for  macadamizing  roads,  over  this  a  mortar  of 
about  two  parts  of  sand  to  one  of  lime  was  carefully  spread  to- 
the  thickness  of  one  and  one-half  to  two  inches,  this  was 
allowed  to  remain  for  twenty-four  hours ;  or  until  the  surface 
had  become  quite  dry.  It  would  probably  take  longer  in  this 
climate,  where  there  is  more  moisture  in  the  air.  The  floor  was  then 
thoroughly  pounded  with  a  block  of  wood  one  foot  square  hav- 
ing a  handle  so  that  a  man  could  stand  while  using  it.  The 
whole  surface  was  beaten  over  with  this  ram  until  it  was  again 
as  soft  and  moist  as  when  first  laid.  This  operation  of  ramming 
brought  the  water  in  the  mortar  to  the  surface,  so  as  to  form  a  layer 
of  semi-fluid  substance  on  the  top.  The  floor  was  again  allowed 
to  dry :  and  again  beaten  over  each  day  for  a  week  when  the 


flo  POWELL'S  FOUNDATIONS 

operation  brought  only  slight  amount  of  moisture  to  the  surface. 
Immediately  after  the  last  pounding  the  whole  surface  was 
powdered  with  a  thin  layer  of  red  ochre  evenly  sifted  on  and 
then  polished  as  follows  : 

A  smooth,  nearly  flat  water-worn  stone,  a  little  larger  than 
the  ram  was  selected  from  the  bed  of  a  stream,  and  with  this 
the  whole  floor  was  laboriously  gone  over ;  rubbing  down  and 
leaving  the  surface  of  the  lime  as  smooth  as  a  piece  of  polished 
stone  ;  the  red  of  the  ochre  making  it  of  a  rich  brown  color. 

In  less  than  a  week  the  floors  made  in  this  way  were  suffi- 
ciently hard  to  bear  the  weight  of  a  horse  without  indentation. 

Roofs  are  made  in  the  same  manner ;  these  roofs  are  perfect- 
ly water-tight.  In  the  city  of  Monterey  sidewalks  of  the  princi- 
pal streets  are  made  in  the  same  manner :  some  of  them  have 
lasted  for  years,  wearing  through  like  a  stone.  The  great  dura- 
bility and  strength  of  these  floors  and  roofs  is  entirely  owing  to 
the  pounding  operation  as  herein  described,  as  the  same  ma- 
terials were  tried  in  the  ordinary  way  without  success." 

This  method  does  not  seem  to  have  been  used  in  this  section 
of  country. 

Selenitic  Mortar  or  Cement. — By  the  Selenitic  process  of 
mortar  making,  ordinary  limes  can  be  made  into  mortar  that, 
instead  of  slacking  with  heat  and  considerable  expansion,  will 
have  the  action  of  cement  imparted  to  them  ;  with  the  further 
advantage  that  they  will  bear  a  larger  proportion  of  sand  than 
can  be  mixed  with  cements  without  the  strength  of  the  cement 
being  materially  affected.  But  as  simple  as  the  process  is,  it  re- 
quires to  be  thoroughly  understood  or  failure  will  be  the  result. 
This  process  Captain  Hyde  Scott,  Royal  Engineer  of  England, 
seems  to  have  brought  into  use  some  twenty  years  ago. 

In  the  selenitic  process,  ordinary  stone  limes,  containing  not 
less  than  twenty  per  cent,  of  clay — such  as  the  lias  limes  of  Eng- 
land and  those  which  come  from  the  lower  chalk  beds ;  for  in- 
stance Dorking,  Burham  and  Mailing  limes — are  made  to  slack 
without  heat  and  without  expansion ;  to  carry  twice  as  much 
sand,  and  in  a  short  time  to  attain  a  considerably  greater  degree 
of  strength  than  can  be  got  from  the  same  limes  used  in  the  ordinary 
way.  This  is  all  brought  about  by  merely  adding  a  small  propor- 


AND    FOUNDATION   WALLS.  Ilr 

tion  of  sulphate  of  lime  in  the  shape  of  plaster  of  paris.  The 
sulphate  of  lime  must  be  brought  in  contact  with  the  ordinary 
lime  while  it  is  in  an  anhydrous  condition,  or  in  other  words,  be- 
fore the  lime  has  been  slacked.  The  proportion  of  plaster  of 
paris  required  to  be  used  is  very  small,  about  one-twentieth  the 
bulk  of  the  lime,  if  the  lime  contains  twenty  per  cent,  of  clav 
There  is  only  one  way  of  mixing  them,  and  that  is  by  mixing 
the  requisite  amount  of  plaster  of  paris,  or  a  certain  proportion 
of  it,  before  the  water  is  added  to  the  quick-lime.  Of  course  it 
is  understood  that  the  lime  used  must  be  ground. 

Selenitic  Clay. — Limes  such  as  those  obtained  from  the  upper 
chalk  formations,  which  contain  less  than  twenty  percent,  of  clay 
mixed  with  them,  require  the  addition  of  too  large  a  proportion 
of  plaster  of  paris  to  effectually  prevent  heating  and  expansion  in 
the  process  of  slacking.  Consequently  this  deficiency  has  to  be 
made  good  by  the  addition  of  what  is  called  "selenitic  clay,"  which 
consists  of  a  marly  clay  or  shale,  well  burned  and  ground  to 
powder ;  as  much  as  two  bushels  of  this  selenitic  clay  may  be 
mixed  with  one  bushel  of  lime. 

Mixing  Selenitic  Mortar  and  Concrete. — The  best  method  of 
mixing  is  to  stir  up  one  pint  of  plaster  of  paris  in  a  two-gallon  pail  of 
water  and  empty  into  the  pan  of  a  mortar  mill  (a  five-foot  mill 
is  a  good  size),  or  use  an  ordinary  plaster  tub,  then  add  four  gal- 
lons of  water  only ;  let  the  pan  take  three  or  four  turns,  and 
then  add  one  bushel  of  prepared  lime ;  and  when  reduced  to  a 
creamy  paste  put  in  the  sand  or  other  material  used,  and  con- 
tinue mixing  for  ten  minutes.  If  unprepared  lime  is  used  the 
only  difference  would  be  that  about  three  pints  of  plaster  would 
be  added  to  the  water  in  place  of  one. 

Proportion  of  Sand  to  Lime. — In  ordinary  mortar  making, 
only  two  or  three  parts  of  sand  can  be  advantageously  mixed 
with  one  of  lime ;  and  the  larger  proportion  of  sand  only  with 
the  purer  limes  :  whilst  with  the  selenitic  process,  we  find  from 
four  to  six  parts  of  sand  to  one  of  lime  gives  the  best  and 
strongest  results,  but  the  lime  for  this  process  should  be  ground 
as  it  can  be  worked  better :  if  it  is  not  convenient  to  have  it 
ground  then  make  as  before  mentioned. 


IJ2  POWELL'S  FOUNDATIONS 


Thrusting]  Tensile  I  Pulling  two 
stress.  stress,  \bricks  apart* 
917  Ibs.  "TTGlbsTl  134  Ibs. 


'1657  Ibs. 


f  360  Ibs.      J3291h° 


Common  Mortar :  1  Lime,  2  Sand, . .  • 
Selenitic  Mortar :  1  Lime,  6  Sand, . . . 

*  Base  area  7.84  square  inches. 

t  Section  area  5  square  inches. 

J  Area  of  point  of  contact  equal  18.5  square  inches. 

EXPERIMENT  MADE  WITH  LEE'S  DURHAM  (ENGLISH)  LIME. 

Concrete  Construction.  —  On  the  Chester  sewage  works^ 
England,  in  reference  to  the  construction  of  Tanks,  the  Engi 
neer  states :  "Cement  concrete  has  been  resorted  to  as  a  sub- 
stitute for  brickwork;  and  as  a  substitute  it  may  succeed 
well  enough  provided  the  persons  engaged  in  the  performance 
of  the  work  have  had  experience  in  the  use  of  the  materials  and 
take  a  personal  interest  in  their  work." 

First,  as  to  the  Cement  Concrete. — The  concrete  was  said  to 
have  been  composed  of  the  following  measured  proportions  : 
gravel  six  parts,  sand  one  part,  cement  one  part.  If  the  cement 
was  reliable  these  proportions  ought  to  result  in  first-class  con- 
crete. I  prefer  the  Lias  cement  if  properly  manufactured — it 
is  made  of  the  Lias  limestone  of  Warwickshire. 

Second,  as  to  the  Lime  Concrete. — This  was  understood  to  have 
been  made  in  the  following  measured  proportions :  gravel 
five  parts,  sand  uncertain  and  variable  but  in  small  quantities, 
Rugby  or  Holywell  ground  lime  one  part.  These  proportions 
formed  a  rich  concrete  which  may  have  been  improved  in  its 
final  hardening  properties  by  a  larger  proportion  of  sharp  sand. 
I  prefer  also  that  the  lime  and  sand  shall  be  made  into  a  well 
mixed  mortar  before  being  added  to  the  gravel.  The  strength 
of  all  concrete  depends  on  the  intimate  blending  of  angular  sand 
with  the  cementitious  matter,  for  without  that  a  proper  crystal- 
lization is  not  obtained. 

Third,  as  to  the  Mortar. — This  was  stated  to  consist  of :  lime 
two  parts  and  sand  two  parts,  cinders  one  part.  This  was  not 
a  good  material.  The  sand  was  in  fact  crushed  sandstone,  and 
the  cinders  were  really  slags  of  steam  boilers.  These'  were 
ground  with  the  lime  under  edgestones  until  the  whole  was  re- 
duced to  an  impalpable  mixture,  rather  like  limey  mud.  The 
sand  should  have  been  sharp  and  angular,  the  cinders  should 


AND    FOUNDATION    WALLS.  Hj 

have  been  smith's  ashes,  containing  the  usual  proportion  of  iron 
oxides.  Hand  made  or  well  pegged  mortar  is  to  be  preferred  for 
engineering  purposes  to  finely  crushed  mortar. 

ANCIENT   CEMENTS. 
Abstract  of  Article  by  Arthur  Beckwith,  C.  E. 

"*  The  monuments  of  Egypt  present  one  of  the  oldest  exam- 
ples of  the  use  of  lime  for  constructions.  The  mortar  which 
joins  the  stone  of  the  Pyramid  of  Cheops  is  precisely  similar  "to 
modern  mortars  made  of  sand  and  lime.  In  limiting  the  u^e  of 
mortar  to  filling  narrow  joints  which  separate  immense  blocks, 
and  thereby  reducing  almost  to  insignificance  the  part  which  it  has 
to  play,  the  Egyptians  seemed  to  forestall  the  influence  of  a  dry 
and  burning  climate.  Time  has  justified  their  prudence  in  this 
respect,  for  the  works  erected  on  the  banks  of  the  Nile  by  the 
Romans,  made  of  small  materials  and  presenting  many  joints, 
have  left  but  faint  traces,  whilst  some  Egyptian  temples  still 
present  themselves  intact  to  our  admiration. 

Unqualified  praise  has  often  been  given  to  the  excellence  of 
Roman  mortar,  and  the  belief  is  sometimes  expressed  that  all 
we  can  hope  to  do  is  to  regain  the  secret  of  making  mortar  once 
possessed  by  the  Romans.  It  is  a  common  remark  that  "Roman 
mortar  has  lasted  for  eighteen  centuries,  whilst  a  number  of 
modern  buildings  are  in  a  deplorable  state  of  preservation." 

To  make  a  fair  comparison,  we  should,  however,  only  cite  sim- 
ilar constructions,  and  then  we  are  comforted  by  these  words 
of  Pliny:  "The  cause  which  makes  so  many  houses  fall  in 
Rome,  resides  in  the  bad  quality  of  the  cement." 

The  knowledge  of  the  properties  of  lime  descended  from 
Egypt  to  Greece,  where  the  exigences  of  the  climate  and  the  in- 
genuity of  the  people  brought  forth  many  of  its  uses,  unknown 
to  Egypt. 

Subsequently  Greek  colonies  imported  and  popularized  their 
processes  in  Italy ;  and  Roman  architects,  like  Vitruvius,  cite 
the  names  of  Greek  authors  on  the  art  of  construction.  Their 
names  alone  have  come  down  to  us,  but  Vitruvius  had  full  access 
to  them,  and  in  our  inquiry  after  the  knowledge  of  mortar  pos- 

-»  From  the  proceedings  of  the  American  Society  of  Civil  Engineers. 


H4  POWELL'S  FOUNDATIONS 

sessed  by  the  Romans,  it  is  to  him  that  we  must  refer  for  infor- 
mation. Indeed,  he  has  left  us  a  detailed  table  of  precepts  used 
by  the  builders  of  Greece  and  Rome,  which  do  not  justify  our 
unreserved  admiration ;  everything  relating  to  lime,  sand  and 
pozzolana  is  clearly  treated  therein. 

We  may  safely  affirm,  with  Vitruvius,  that  the  Romans  made 
use  of  the  lime,  sand  and  materials  of  the  countries  where  they 
built ;  that  they  considered  the  best  lime  to  be  produced  from 
hard  and  pure  marble,  /.  e.,  the  fattest  lime  known  ;  that  in  Italy 
they  mixed  it  with  pozzolana  when  used  for  hydraulic  purposes, 
and  that  out  of  Italy  they  replaced  the  pozzolana  from  Vesuvius, 
by  powdered  brick  or  tile. 

Roman  mortars,  when  examined  today  are  found  to  bear  a 
distinct  resemblance  to  each  other  ;  they  may  be  recognized  by 
the  presence  of  coarse  sand  mixed  with  gravel ;  lumps  of  lime 
are  so  often  to  be  met  with,  that  incomplete  slaking  will  alone 
account  for  them.  Mortars  laid  in  damp  spots  for  cisterns  and 
pavements  were  composed  of  bricks  in  small  fragments  mixed 
with  fat  lime  ;  this  concrete  required  to  be  compacted  by  pound- 
ing and  left  to  dry — the  surface  was  then  scraped,  polished  and 
painted — evidently  to  prevent  the  dissolution  of  lime  by  water. 

It  will  be  seen  by  this  that  what  we. term  hydraulic  lime,  and 
also  the  modern  product  of  cement,  were  unknown  to  the  Rom- 
ans. 

It  is  important  to  refute  the  belief  that  methods  may  have  been 
known  to  them  of  which  we  have  lost  the  secret.  When  the  de- 
cay of  arts  followed  upon  the  downfall  of  the  Roman  Empire, 
houses  nevertheless  continued  to  be  built,  and  the  familiar  pro- 
cesses under  the  eye  of  the  workman  must  have  been  transmit- 
ted from  father  to  son.  So  true  is  this,  that  today  Italian  ma- 
sons, who  certainly  have  not  read  Vitruvius,  make  coatings  for 
cisterns  and  concrete  floors  in  the  very  same  manner  as  may 
still  be  seen  in  the  ancient  ruins  of  Rome. 

Neither  is  it  true  that  Roman  mortar  is  uniformly  good.  Its 
strength  of  cohesion  varies  in  different  examples  from  35  to  85 
Ibs.  per  square  inch  to  100  and  160  Ibs.,  or  as  much  as  500  per 
cent. 

In  the  middle  ages  a  volcanic  conglomerate  from  the  banks 
of  the  Rhine,  named  traass,  was  substituted  for  the  pozzolana 


AND    FOUNDATION    WALLS.  II5 

of  Italy,  and  mortar  was  made  of  fat  lime,  mixed  with  traass, 
to  render  it  hydraulic. 

Many  castles  erected  during  that  period  stand  well  today  ; 
the  well-known  castle  of  the  Bastile,  erected  in  1369-83,  which 
after  withstanding  a  siege  required  the  use  of  powder  for  its  de- 
struction in  1789,  was  found  to  be  extremely  solid  even  in  the 
interior  walls. 

It  would  seem,  then,  that  the  secret  of  the  Romans  was 
known  also  in  those  times,  and  could  have  been  lost  only  at  the 
Renaissance,  when  least  of  all  such  a  supposition  is  probable. 

At  what  period  were  first  used  certain  limestones,  having  the 
property  of  producing  a  lime  which  will  harden  under  water ; 
it  is  not  precisely  known  ;  the  first  use  of  cement  stone  is  equally 
obscure. 

In  1796  Messrs.  Parker  and  Wyatts  began  to  manufacture 
from  egg-shaped  limestones  found  near  London,  a  product  known 
later  as  Roman  Cement,  and  which  was  soon  received  with  great 
favor  throughout  Europe ;  but  neither  the  producers  nor  the 
consumers  offered  any  explanation  of  its  merits. 

Not  until  1818  and  the  following  years  was  the  true  explana- 
tion given  to  the  hydraulic  properties  of  limes  and  cements 
when  Vicat  published  his  discoveries. 

Before  that,  in  1756,  when  Smeaton  was  preparing  the  ardu- 
ous and  bold  construction  of  the  Eddystone  Lighthouse,  this 
celebrated  engineer  examined  with  scrupulous  attention  the  nat- 
ural hydraulic  lime  of  Aberthaw.  Treated  by  acids  it  left  a 
residue  "which  appeared  to  be  a  bluish  clay,  weighing  about  one- 
eighth  of  the  total  weight  of  the  stone." 

In  1786,  Saussure  attributed  the  hydraulic  properties  of  some 
limes  of  Savoy  to  the  combined  influence  of  manganese,  quartz, 
and  even  clay ;  but  he  left  his  opinions  in  the  mere  state  of  con- 
jectures. 

Finally,  Descostils,  in  1813,  having  discovered  a  considerable 
proportion  of  finely  divided  silica  in  the  lime  of  Senonches,  at- 
tributed the  well  known  hydraulicity  of  that  lime  to  the  silica  it 
contained. 

But  the  conjectures  of  Smeaton,  of  Saussure  and  of  Descostils 
were  vague  ;  they  rested  upon  no  proofs,  and  found  no  applica- 
tions in  practice. 


u6 


POWELL'S  FOUNDATIONS 


The  discoveries  of  Vicat  attained  their  immediate  object,  for 
in  a  short  time  artificial  hydraulic  lime  of  excellent  quality  was 
manufactured  on  a  large  scale  under  his  direction,  and  a  few 
years  later  he  indicated  as  many  as  400  quarries  in  France  where 
hydraulic  limestones  were  to  be  found. 

The  following  valuable  selection  is  from  an  English  journal : 

Rapidity  of  Set. — Very  rapid  setting  and  great  strength  are 
not  met  with  in  the  same  cement ;  but  in  many  cases  the  quick- 
er setting  and  lighter  cements  are  most  useful.  It  is  believed 
that  before  long  light  Portland  cements  will  be  manufactured, 
capable  of  competing  with  the  Roman  cements,  in  quickness  of 
setting,  and  surpassing  them  in  uniformity  of  quality. 

The  following  table  contains  the  result  of  a  series  of  experi- 
ments made  by  Mr.  J.  GRANT,  C.  E.,  London,  England,  with 
Portland  cement,  weighing  123  Ibs.  per  bushel : — 


Average  Breaking  Test  of  Ten  Specimens. 


Age. 

Neat  Cement. 

1  Cement,  1  Sand. 

7  da 
Imc 
3 
6 
9 
12 

r 

5 
6 

7 

Ibs. 
817-1 
935-8 
1055-9 
1176-6 
1219-5 
1229-7 
1324-9 
1314-4 
1312-6 
1306-8 
1308-0 
1327-3 

Ibs. 
353-2 
452-5 
547-5 
640-3 
692-4 
716-6 
790-3 
784-7 
81S-1 
821-0 
819-5 
803-6 

Ultll                              %  

The  whole  of  the  specimens  were  kept  in  water  from  the  time 
of  their  being  made  up  to  the  time  of  testing,  and  the  breaking 
weight  applies  to  a  sectional  area  of  i  1-2  inches  square,  or  2.25 
inches  super.  It  appears  from  these  experiments  that  neat  ce- 
ment of  123  Ibs.  per  bushel  took  two  years  to  attain  its  full 
strength,  whilst  the  admixture  of  sand,  in  addition  to  weakening 
the  specimens,  also  delayed  their  attaining  their  maximum  pow- 
ers of  resistance. 


AND    FOUNDATION  WALLS.  1 17 

Color.— A  dull  earthy  color  denotes  an  excess  of  clay  ;  whilst 
tool  ight  a  color  is  the  result  of  either  under-burning  or  an  ex- 
cess of  lime,  or  of  both  these  faults  combined. 

Packing  the  Cement.— Since  Portland,  unlike  Roman  cement, 
improves  within  certain  limits  by  exposure  to  the  air,  it  need 
not  be  packed  in  air-tight  casks  (except  for  exportation),  but 
kept  dry.  The  casks  in  which  it  is  packed  generally  contain 
four  cwt.,  and  the  bags  two  cwt. 

Water  for  Mixing. — Salt  water  does  no  injury  to  the  strength 
of  the  cement,  but  must  be  avoided  where  efflorescence  or  damp 
on  the  surface  would  be  objectionable. 

Both  cement,  mortar  and  concrete  should  be  made  with  as 
little  water  as  will  suffice  to  make  the  whole  cling  together. 
When  too  much  is  used,  the  finer  particles  of  the  cement  get 
separated  from  the  rest  and  float  away,  or  on  the  surface  in  the 
form  of  a  slime.  In  mixing  concrete,  if  the  ballast  is  porous  and 
dry,  more  water  will  be  required  than  if  damp  or  non-absorbent. 

Sand,  Grayel,  and  other  Materials  for  Mixing  with  Portland 
Cement. — Experience  has  shown  that  porous  materials,  by  allow- 
ing the  cement  to  enter  the  pores,  and  so  retain  a  firm  hold  on 
them,  are  the  best  for  mixing  with  cement:  thus,  well-burnt 
broken  bricks,  clay  ballast,  furnace  slag  or  breeze,  will  form  a 
stronger  concrete  than  if  made  with  the  harder  but  smoother 
and  less  porous  stones  in  gravel  or  shingle ;  but  it  must  be 
borne  in  mind  that  in  such  cases  a  slightly  larger  proportion  of 
cement  is  advisable  to  compensate  for  what  is  absorbed  by  the 
pores  of  the  material.  No  importance  need  be  attached  to  the 
shape  of  the  particles  of  sand  or  other  materials  used — such  as 
whether  angular  or  water-worn — though  a  certain  roughness  of 
surface  gives  a  better  hold  to  the  cement  than  if  too  smooth. 
The  presence  of  dirt,  such  as  loam,  clay  and  vegetable  matter 
liable  to  decay,  has  a  prejudicial  effect  upon  cement,  and  sensi- 
bly weakens  either  mortar  or  concrete. 

The  gravel,  broken  stone,  or  other  material  used  in  making 
concrete,  should  have  sufficient  small  stuff  and  sand  mixed  with 
it  to  fill  up  the  interstices  between  the  larger  pieces.  When 
this  is  not  already  the  case,  the  amount  of  small  stuff  and  sand 


U8  POWELL'S  FOUNDATIONS 

which  ought  to  be  added  may  be  ascertained  by  filling  up  any 
suitable  measure,  of  uniform  section  from  top  to  bottom,  with 
the  gravel,  &c.,  striking  it  level  with  the  top,  and  then  adding 
as  much  water  as  the  measure  will  contain.  The  water  may 
then  be  run  off  through  a  hole  in  the  bottom  of  the  measure, 
the  gravel,  &c.,  removed  from  it,  and  the  water  replaced  in  it ; 
the  amount  of  water  expressed  in  terms  of  the  internal  height 
of  the  measure  will  be  the  proportion  of  small  stuff  which  should 
be  added  to  the  ballast. 

Proportion  of  Cement  in  Mortar  and  Concrete.— As  cement  is 
not  used,  on  account  of  the  cost,  unless  special  strength  is  re- 
quired, the  proportions  in  general  use  are  i  cement  to  either  I 
or  2  sand ;  below  this  the  advantage  gained  by  its  use  diminish- 
es rapidly.  In  general  terms  neat  cement  is  one-third  stronger 
than  if  mixed  with  I  sand,  and  twice  as  strong  as  when  mixed 
with  2  sand. 

For  concrete,  I  cement  to  10  or  even  12  gravel,  or  other  ma- 
terial, is  sufficient  for  masses  in  foundations,  dock  walls,  &c.; 
i  to  8  or  6,  for  ordinary  walls,  according  to  their  thickness  ;  and 
i  to  4  for  floors,  and  other  places  where  great  transverse  strength 
is  necessary. 

Mixing  and  Laying  Portland  Cement  Concrete. — The  best 
method  of  mixing  concrete  in  large  quantities  is,  taking  a  meas- 
ure of  convenient  capacity  for  one  mixing,  to  half  fill  the  meas- 
ure with  the  broken  .ballast,  or  other  material,  and  then  add  the 
cement ;  finally  filling  up  the  measure  with  the  ballast.  The 
measure  should  then  be  lifted  off,  when  the  whole  will  fall  into 
a  heap,  the  cement  partially  mixing  with  the  ballast  in  so  doing, 
and  not  being  so  liable  to  get  wasted  by  being  blown  about  by 
the  wind,  as  when  emptied  over  the  top  of  the  ballast  heap.  The 
whole  should  be  turned  over  twice  dry,  and  then  shovelled  to  a 
third  heap,  sufficient  water  only  being  added  in  so  doing — by 
sprinkling  from  the  rose  of  a  watering-pot — to  make  the  ingre- 
dient cling  together  in  a  pasty  mass.  The  floor  upon  which  it 
is  mixed  should  be  hard  and  clean. 

The  concrete  may  either  be  wheeled  off  and  deposited  in  po- 
sition, or,  if  more  convenient,  may  be  thrown  down,  but  in  both 
cases,  more  especially  in  the  former,  it  is  advisable  to  beat  it 


AND   FOUNDATION   WALLS.  II£ 

doun  lightly  with  wooden  beaters  until  the  moisture  comes  to 
the  surface. 

On  no  account  should  it  be  sent  down  a  shoot,  or  the  finer 
and  coarser  ingredients  will  get  separated  in  the  descent,  the 
former  clinging  more  to  the  sides  of  the  shoot,  whilst  the  latter 
will  reach  the  bottom  first,  and  get  shot  out  into  a  heap  by  them- 
selves. 

Not  to  be  disturbed  whilst  Setting.— When  cement-work  has 
once  been  laid,  it  must  not  be  touched  until  quite  hard,  for  its 
strength  will  be  materially  affected  if  the  particles  are  disturbed 
after  the  process  of  setting  has  commenced. 

Bricks,  Stones,  &c.,  to  be  Wetted. — All  absorbent  surfaces  or 
materials,  with  which  cement  is  to  come  in  contact,  should  be 
well  wetted,  or  they  will  rob  the  cement  of  the  moisture  neces- 
sary to  enable  it  to  set  hard ;  but  the  water  should  not  be  oozing 
out  of  them,  or  the  cement,  being  unable  to  enter  their  pores, 
will  fail  to  adhere  properly  to  them.  For  this  reason  broken 
brick  ballast,  &c.,  if  quite  dry,  will  require  more  water  in  con- 
crete making,  than  if  already  damp,  and  old  dry  walls  will  re- 
quire more  wetting  than  new  or  external  damp  walls. 

Cement  to  be  kept  Damp  while  Setting. — Cement-work  must 
be  kept  damp  until  set  quite  hard,  or  it  will  become  rotten  from 
the  evaporation  of  the  water  of  mixing,  which  is  essential  to  the 
proper  setting  of  the  cement :  hence  the  most  suitable  time  for 
executing  cement-work  is  in  damp  weather.  When  the  work 
has  to  be  done  in  dry  weather,  special  care  is  necessary  to  keep 
it  damp,  and  to  protect  it  from  the  sun's  rays.  Flat  surfaces, 
such  as  floors,  paving,  &c.,  should,  if  practicable,  be  kept  flood- 
ed with  water  or  covered  with  a  layer  of  sawdust  or  sand  3  or  4 
inches  thick,  which  should  be  kept  quite  damp  for  at  least  sev- 
en days,  or  until  the  cement  has  become  quite  hard.  In  sur- 
faces exposed  to  traffic  this  is  most  important,  as  the  cement,  if 
at  all  perished,  will  soon  wear  away. 

Avoid  imbedding  Iron  in  Cement.— Cement  mixed  with  sand 
and  other  materials  is  porous,  admitting  both  moisture  and  air ; 
iron,  therefore  imbedded  in  cement-work,  is  liable  to  rust,  and 


!2o  POWELL'S  FOUNDATIONS 

the  expansive  force  accompanying  this  process  will  split  up  cem- 
ent, stone,  or  any  similar  unyielding  material ;  if  the  iron  is  gal- 
vanized it  is  not  affected  by  the  cement. 

DESCRIPTION  OF  PORTLAND  CEMENT. 
Characteristics  of  good  Portland  Cement. 

The  following  explanations  about  the  uses  of  Portland  cement 
will  apply  to  a  great  extent  to  all  other  cements. 

1.  Fineness. — It  should,  when  passed  through  a  copper  wire 
sieve  of  2,500  meshes  per  square  inch,  not  leave  more  than  20 
per  cent,  of  grit  behind.     The  cement  sifted  should  not  be  less 
than  25  Ibs.,  taken  from- different  bags,  or  from  different  parts 
of  the  heap  if  stored  in  bulk.     After  a  little  experience,  a  well- 
ground  cement  may  readily  be  recognized  by  the  absence  of 
grit  when  rubbed  between  the  fingers. 

2.  Expanding  or  Contracting  in  Setting. — When  made    up 
without  sand  or  excess  of  water,  and  filled  up  level  with  the  top 
of  a  glass  or  similar  vessel,  it  should  set  hard  without  cracking 
the  vessel,  rising  or  sinking,  or  getting  loose  in  it,  or  showing 
any  signs  of  cracks  in  the  cement  itself. 

3.  Strength — When  made  up  without  sand,  with  as  little 
water  as  possible,  and  filled  into  moulds,  it  should,  after  seven 
consecutive  days  in  water,  give  an  ultimate  strength,  under  a 
tensile  stress  slowly  applied,  of  250  Ibs.  per  square  inch  of  frac- 
tured section,  the  immersion  in  water  to  commence  as  soon  as 
the  cement  blocks  will  bear  removing  from  the  moulds,  which 
should  not  exceed  twenty-four  hours  after  the  moulds  have  been 
filled. 

When  time  will  not  admit  of  this  test  being  applied,  a  very 
fair  idea  of  the  strength  of  the  cement  can  be  arrived  at  from 
its  weight,  which  should  not  be  less  than  108  Ibs.  per  imperial 
striked  bushel,  filled  up  as  lightly  as  possible,  by  pouring  the 
cement  down  an  inclined  board,  or  through  a  wooden  hopper, 
about  i  foot  square  at  top,  i  inch  square  at  bottom,  and  i  foot  deep. 
The  hopper  should  be  suspended  with  the  point  of  discharge  6 
inches  above  the  top  of  the  bushel  measure,  which  should  stand 


AND   FOUNDATION   WALLS.  121 

on  a  firm  base  and  not  on  any  vibrating  floor,  and  should  not  be 
touched  until  the  cement  in  it  has  been  finally  struck  level  with 
the  top  with  a  straight-edge.  The  cement  weighed  should  be 
taken  from  different  bags,  or  from  different  parts  of  the  heap  if 
stored  in  bulk. 

Rapidity  of  Set. — When  made  up  into  cakes  about  half  an 
inch  thick,  without  any  sand  or  excess  of  water,  the  cement 
should  set  hard  within  24  hours,  either  in  or  out  of  water,  with- 
out showing  any  signs  of  cracks. 

Color. — The  color  of  good  Portland  cement  is  a  bluish-grey ; 
if  dark  and  earthy,  or  of  too  light  a  color,  it  is  not  to  be  trusted. 
When  made  up  without  sand  and  set  hard,  it  should  show  the 
same  bluish-grey  color  without  any  brown  specks  or  stains. 

Explanatory  Remarks. 

Fineness. — A  high  degree  of  fineness  is  necessary  to  the  com- 
plete and  simultaneous  setting  of  all  the  particles  throughout 
the  mass.  When  insufficiently  ground,  the  fine  particles  set 
first,  then  the  coarser  grit,  and  lastly  the  little  hard  lumps  ;  and 
it  is  this  process  going  on,  after  the  surrounding  particles  have 
already  set  hard,  which  often  shows  itself  all  over  the  surface 
by  the  "blowing"  or  bursting  out  of  numberless  pustules,  or 
the  cracking  of  the  entire  body  of  the  cement. 

Some  foreign  cements  allow  of  85  per  cent,  passing  through 
a  No.  60  gauge,  or  3,600  meshes  per  superficial  inch  ;  but  cements 
of  such  extreme  fineness  are  under-burnt,  and  therefore  weigh 
light,  and  are  deficient  in  strength,  though  often  rapid  in  setting. 
The  wear  and  tear  to  the  machinery  in  grinding  well-burnt  cem- 
ents to  such  extreme  fineness  would  render  them  too  costly  to 
be  marketable. 

Expanding  or  Contracting  in  Setting.— The  test  for  expansion 
or  contraction  in  setting  is  very  simple,  and  one  which  should 
on  no  account  be  omitted,  for  these  are  about  the  most  serious 
defects  to  which  Portland  cements  are  liable,  though  for  the 
most  part  no  steps  are  taken  to  guard  against  them. 

Expansion  in  setting  is  due  to  the  presence  of  free  lime  in  the 
cement — owing  either  to  more  lime  having  been  used  in  its  man- 


,22  POWELL'S    FOUNDATIONS 

ufacture  than  can  chemically  combine  with  the  clay— to  imper- 
fect mixing  of  the  lime  with  the  clay,  or  to  the  burning  not  hav- 
ing been  carried  to  a  sufficient  extent  to  enable  the  lime  and  clay 
to  combine  together. 

Contraction  in  setting,  which  is  not  nearly  so  often  met  with, 
is  due  to  an  excess  of  clay,  and,  as  there  is  no  remedy  for  this 
evil,  the  cement  must  be  rejected. 

The  tendency  to  expand  in  setting  is  a  very  common  fault  in 
fresh-ground  cements,  especially  those  of  the  heaviest  and  strong- 
est descriptions,  owing  to  the  large  proportion  of  lime  used  in 
their  manufacture,  which,  if  in  excess,  as  already  explained — or 
even  locally  in  excess,  owing  to  imperfect  mixing — is  present  in 
the  cement  in  the  form  of  free  lime,  which  heats  and  expands 
considerably  in  the  process  of  slaking.  However,  if  the  cement 
is  otherwise  good,  this  evil  can  be  remedied  by  spreading  it  out 
on  a  dry  floor,  under  cover,  and  turning  it  over  occasionally,  to 
allow  of  its  air  slaking  or  "cooling." 

"When  delivered  on  the  works  for  use,  Portland  cement  should 
always  be  shot  from  the  bags  on  to  a  wooden  floor — to  a  depth 
not  exceeding  4  feet — and  be  permitted  to  remain  at  least  three 
weeks  before  it  is  allowed  to  be  used  for  any  purpose.  While 
so  kept,  fresh  Portland  cement  increases  considerably  in  bulk — 
probably  10  per  cent. — without  any  diminution  of  its  strength  \ 
so  that  it  should  be  to  the  advantage  of  a  contractor  to  store  his 
cement  before  using  it,  even  if  he  were  not  required  to  do  so  by 
the  engineer.  I  can  hardly  impress  too  strongly  upon  you  the 
importance  of  avoiding  the  use  of  fresh  cement  for  any  purpose 
whatever." 

Many  a  good,  strong  cement  which,  when  first  delivered,  would 
heat  in  mixing  and  expand  in  setting,  would,  after  exposure  to 
the  air  for  a  time,  stand  the  test  for  expansio-n  perfectly. 

Tests  of  Cements — F.  O.  Norton,  Civil  Engineer,  who  has 
made  a  large  number  of  experiments  on  American  cements,  has 
obtained  a  class  of  comparative  results,  which  gives  a  clear 
knowledge  of  the  magnesian  limestone.  The  principal  deposit 
of  the  magnesian  limestone  producing  a  cement  possessing  hy- 
draulic energy,  occurs  in  the  town  of  Rosendale,  Ulster  Co., 


AND    FOUNDATION   WALLS.  12$ 

New  York.  The  following  tests  were  made  at  the  works  at 
Binne water,  during  the  season  of  1878,  commencing  in  April 
and  continued  for  eight  months. 

Several  times  each  day  a  number  of  briquettes  were  made  of 
the  cement  manufactured  that  day.  The  briquettes  were  mixed  in 
two  ways — in  one  the  cement  was  mixed  with  water  to  form  an 
ordinary  stiff  mortar,  which  was  pressed  in  the  moulds  and 
smoothed  off:  for  the  other  a  very  dry  mixture  was  made. 
Both  mixtures  were  left  in  the  moulds  a  few  minutes,  and  were 
then  pressed  out  with  a  wooden  plunger,  and  left  in  the  air 
thirty  minutes.  They  were  then  put  in  water  and  left  in  water 
until  broken.  5824  briquettes  were  made  and  broken  during 
the  eight  months. 

RESULT  OF  TESTS. 
Tensile  strength  per  square  inch,  represented  in  pounds  on  5824  Briquettes. 


15  1  1    1  2    1   3 
days\  mo.  I  mo.  'TOO. 

1    4 
\  mo. 

~395~ 
380 
500 

3 

mo. 

Vif 

40.-) 
5-20 

i. 

-fioT 
410 
530 

7  1    8 
mo.\  mo. 

<J 

mo. 

To 

mo. 

11 

mo. 

465 
409 

12 
mo. 

IcT 

405 

1878.    Stiff  Mortar,  
"       Dry  Mixture,  
1879.    Stiff  Mortar,   

65 
150 
125 

17ii 
2:50 
1250 

265  1  385 

300    350 

380  \  460 

454 

415 

475 
415 

4f;;> 

415 

470 

4D.-, 

The  briquettes  were  shaped  like  a  dumb-bell  the  breaking  area 
being  one  inch  square. 

Rosendale  cements  of  the  best  qualities  develope  great  hy- 
draulic strength  in  twenty-four  hours,  being  at  that  time  equal  to 
Portland  cement.  The  Portland  cement  gains  rapidly  up  to 
seven  days,  at  the  end  of  a  month  the  Rosendale  approaches 
the  Portland  and  the  difference  between  the  two  is  changed  after 
that  time. 

For  practical  purposes  all  cements  are  generally  used  with  a 
mixture  of  sands.  This  reduction  of  strength  in  round  num- 
bers is  as  follows : 

1  part  of  sand  gives  mortar  1-2  as  strong  as  pure  cement. 

2  «  «  «  «  1-2  "  "  " 

3  u  (t  u  (i  1.4  «  "  " 

4  «  «  «  «  1-5  «  "  " 

5  u  «  «  «  1-6  "  "  " 

The  following  Tests  of  Cements  were  made  in  the  months 
of  Jan.,  Feb.  and  March  of  1882. 


124 


POWELL'S  FOUNDATIONS 

THESE  TESTS  WERE  MADE  IX  NEW  YORK. 


.Tensile  etral 

' 

a 

of  Ibs.  per 

Brand. 

sL,. 

* 

| 

Time. 

£ 

w 

Time. 

% 

"S 

Time. 

t 

t 

square  inch. 

j 

Remarks. 

Swedish, 
Gillingham, 

"  24  h. 
«  24  h. 

80  72 
7S  92 
50  6->, 

7  days 

194|190 
(29240 

;j-<  886 

14  d'y  s  257  160 

30S448 
230,200 

21days 

304306 
390  4'24 

278  292 

Imported  is 
very  good. 

Dyckerhoff, 
Delafleld, 

Laureuceville, 
Kock  Lock, 
Connelly  &Scheffer, 

;';' 

7080 
5648 
5036 
8032 
4024 

I2S  Ilf 

72   56 
233   47 
80|  70 

230240 
214-205 
138  130 
206  f'il 
98  101 

217 
280 

85 
210 
95 

235 
200 
60 

78 
40 

The    longer 
It  stands  the 
better  It  la. 

All  these  cements  are  in  use  in  the  city  of  New  York.  Small 
moulded  pieces  of  cement  of  the  form  of  a  dumb-bell  were  cast 
•with  the  middle  part  I  inch  square.  Each  one  of  these  forms 
were  tested  separately  on  scales  made  for  testing  building  ma- 
terials. 

Hydraulic  Limes  and  Cements. — If  limes  harden  under 
water  in  from  fifteen  to  twenty  days  after  immersion,  they  are 
slightly  hydraulic;  if  from  six  to  eight  days,  simply  hydraulic, 
and  from  one  to  four  days,  eminently  hydraulic.  Hydraulic 
limes  if  not  properly  slacked,  will  sometimes  burst.  It  should 
-all  be  hydrated  before  placing,  which  will  require  more  time  than 
ordinary  lime.  The  different  kinds  act  differently.  There  is 
but  little  heat  developed  in  these  limes  while  slacking. 

The  hydraulic  lime  of  Tiel,  manufactured  in  France,  and  im- 
ported to  this  country  in  barrels  of  from  450  to  600  pounds,  is 
extensively  used,  and  considered  a  very  strong  cement.  It  will 
set  firmly  in  eighteen  to  twenty-four  hours  under  water,  and  in- 
creases in  tensile  strength  from  40  to  160  pounds  per  square 
inch,  and  the  crushing  weight  from  200  to  600  pounds  per  square 
inch.  It  weighs  from  40  to  45  pounds  per  cubic  foot.  The 
slacking  of  100  pounds  of  Tiel  lime  requires  28  pounds  of  water. 

For  Salt- Water  Mortars,  Concrete  nnder  water. — One  part 
•of  Tiel  lime  to  two  parts  of  sand. 

For  Mortars  Exposed  to  Air.— One  part  lime,  three  parts 
sand. 


AND   FOUNDATION   WALLS.  125 

To  form  Betons  and  Concrete  from  the  Mortars  before  men- 
tioned.— Salt-  Water  Concretes. — Two  measures  of  mortar,  thor- 
oughly mixed  with  three  of  broken  stone. 

Fresh-Water  Concretes. — One  measure  of  mortar  to  two  of 
broken  stone. 

Artificial  Blocks. — One  measure  of  mortar  to  two  of  pebbles. 

Portland  Cement  is  made  of  argillaceous  limestones  selected 
for  the  purpose,  or  argillaceous  chalk  or  calcerous  clays,  or 
mixtures  of  artificial  carbonate  of  lime  or  clay,  and  artificial 
mixtures  of  caustic  limes  and  clay. 

It  is  burned  in  kilns  with  a  heat  of  sufficient  duration  and  in- 
tensity to  produce  the  beginning  of  vitrifaction.  After  this  the 
product  is  ground  to  powder.  There  should  be  from  seventy  to 
eighty  per  cent,  carbonate  of  lime,  and  twenty  to  twenty-five  per 
cent,  of  clay,  and  not  less  than  ninety  to  ninety-five  per  cent,  of 
the  lime  and  clay  required  for  a  first  quality  cement.  Hard  car- 
bonates of  lime  are  expensive  to  reduce  to  powder,  yet  hard 
limestones  may  be  used.  Suitable  clay  is  of  more  rare  occur- 
rence than  suitable  limestone,  for  the  reason  the  former  must 
contain  alumina  and  silica,  not  only  in  certain  proportions  but 
in  a  certain  state  of  pulverization. 

For  foundation  walls  on  damp  and  yielding  soils,  also  for  sub- 
marine masonry,  Portland  cement  concrete  is  superior  to  brick- 
work in  strength,  durability  and  economy.  It  is  also  well  suited 
for  sewers,  piers,  abutments,  pavements,  etc.  A  barrel  weighs- 
about  400  pounds,  and  has  a  tensile  strength  of  250  pounds  per 
square  inch,  and  safely  sustains,  after  seven  days  set,  470  pounds 
per  square  inch. 

Concrete  or  Beton  is  a  mixture  of  lime,  sand  and  gravel  or 
broken  stone,  or  hard-burned  broken  brick.  When  cement  is 
used  instead  of  lime,  it  is  known  as  a  cement  concrete. 

The  object  to  be  attained  in  making  hydraulic  concrete  is  to 
give  such  a  sufficiency  of  mortar  as  will  produce  the  aggre- 
gation of  the  whole  mass  of  rough  rubble  materials. 

When  Portland  cement  is  used,  one  part  of  cement  may  be 
used  to  three  parts  of  sand,  and  this  may  be  mixed  with  six 
parts  of  gravel,  stone,  spalls  or  broken  bricks. 


I26  POWELL'S  FOUNDATIONS 

For  Tiel  lime,  lime  three  parts,  sand  five  parts,  two  parts 
broken  stone.  This  is  at  it  was  used  at  the  mole  in  Marseilles 

The  French  Beton  Agglomere.— Cement  in  blocks  consists  of 
1 80  parts  of  sand,  44  parts  of  lime  slacked,  33  parts  of  Portland 
cement,  and  20  parts  of  water.  This  is  most  thoroughly  incor- 
porated. 

Vicat  Cement.— This  artificial  cement 'sets  strongly  in  from 
eight  to  fifteen  hours,  and  is  able  to  stand  great  cold.  Vicat 
mortar,  of  one  part  of  cement  to  three  parts  of  sand,  when  four- 
teen days  old,  sustained  safely  a  pressure  of  300  pounds  per 
square  inch. 

Lafarge  Cement — Weighs  sixty-six  pounds  per  cubic  foot. 
Begins  setting  after  three  to  three  and  a  half  hours  ;  completes 
its  setting  in  twelve  to  eighteen  hours. 

Made  into  Mortar. — One  part  cement  to  two  parts  sand.  Af- 
ter eight  days  setting,  its  tensile  strength  was  found  to  be  142 
pounds  per  square  inch. 

Made  into  Mortar. — One  part  cement,  three  parts  sand.  After 
three  days  setting,  did  not  crush  until  loaded  with  81  pounds 
per  square  inch.  The  same  mixture, 

After  13  days .540  pounds  square  inch,  crushing  load. 

"     33    "    942       "  «         «  "  « 

"     43    «    1049       u  u         u  it  u 

In  practice  it  would  be  safe  to  use  a  working  load  to  the  above 
of  one-quarter  of  the  crushing  load. 

The  resistance  to  rupture  after  twenty  days  exposed  to  the 
air,  is  about  54  pounds  per  square  inch  ;  with  equal  proportions 
of  sand  and  cement  it  falls  to  27  pounds. 

American  and  Foreign  Cements.— 

American  Rosendale from    60  to    70  pounds  cubic  foot. 

English  Portland "      95  to  102      "          "       " 

And  hi  barrels "     400to430       «»       to  barrel. 

French  Portland «      95  to  105       "      cubic  foot. 

Lafarge «      66  to    70       "          "       " 

Tiel  Lime "      52  to    58       "          "       " 


AND    FOUNDATION    WALLS.  \2J 

The  'following  cements  were  made  into  small  blocks,  four 
inches  square  by  one  inch  thick,  and  they  set  as  follows : 

Statine,  French  Cement 15  minutes. 

Pomeranium,  German 13        " 

K  and  S  Portland,  imported 11        " 

White's  "  "        71-2" 

Bosendale,  U.  S 30  to  45        " 

They  were  tested  by  tapping  them  with  a  piece  of  wood,  the 
size  of  a  common  clothes-line  pin;  when  no  impression  was 
made,  they  were  said  to  have  set. 

Keene's  Cement. — An  imported  cement,  is  used  extensively 
for  interior  decorations,  artificial  marble  cornices  and  center- 
pieces. The  superfine  is  of  a  delicate  white,  takes  a  high  pol- 
ish, and  makes  beautiful  scagiola-work.  There  is  a  medium 
quality  used  for  the  same  purpose,  and  used  in  artificial  marbles. 
The  coarse  is  used  for  stucco,  and  has  great  durability ;  also  for 
floors  to  halls,  areas,  passages,  vestibules,  churches,  etc.  It  is 
less  expensive  than  Portland  cement.  One  cask  contains  four 
bushels,  which,  mixed  in  the  proportion  of  one  part  cement, 
and  two  parts  sand,  will  cover  about  fifteen  superficial  yards 
one-half  inch  thick. 

For  Polished  Work  of  Walls. — Use  the  floating  coat  of  equal 
parts  Keene's  coarse  cement  and  sand ;  the  setting  coat  to  be  of 
superfine  one-quarter  inch  thick. 

For  Stucco  on  Brickwork. — For  floating  coat,  one  part  cem- 
ent, and  two  parts  sand.  The  setting  coat  should  be  three- 
sixteenths  inch  thick. 

Where  it  is  required  to  lay  a  coat  of  cement  over  a  floor  sur- 
face, one  barrel  of  Portland  cement,  weighing  about  400  pounds, 
if  used  neat,  will  cover  five  square  yards  of  surface  one  inch 
thick ;  and  when  mixing,  if  there  is  added  two  parts  of  sand,  it 
will  cover  fifteen  square  yards  of  surface  one  inch  thick. 

Rosendale  Cement  Concrete.— One  barrel  Rosendale  cement, 
{300  pounds  weight,  75  pounds  per  bushel;)  three  barrels  of 
sharp,  gritty  and  damp  sand;  five  barrels  of  broken  stone;  will 
•sustain  a  load  of  40  pounds  square  inch  when  set. 

Portland  Cement  Concrete.— One  barrel  of  Portland  cement, 
(400  pounds,  say  five  cubic  feet ;)  one  barrel  of  Thomaston  lime, 
eight  barrels  of  sand,  twelve  barrels  of  broken  stone;  will  sus- 
tain a  load  of  50  pounds  per  square  inch  when  set. 


I2g  POWELL'S  FOUNDATIONS 

Rosendale  cement  weighs  about  75  pounds  per  bushel ;  Port- 
land cement  will  average  116  pounds  per  bushel,  when  90  per 
cent.  fine.  Dark  cement  appears  to  be  the  strongest.  Fine 
quality  cements  are  now  manufactured  in  many  parts  of  the 
United  States.  The  best  are  from  Rosendale  cements  of  New 
York  and  New  Jersey ;  Cumberland,  Maryland ;  Round  Top,  Han- 
cock, in  Maryland ;  Sandusky,  Ohio ;  and  Shepherdstown,  Vir- 
ginia. 

Nearly  all  hydraulic  limes  and  cements,  after  being  packed  in 
barrels,  will  lose  their  energy  by  exposure  or  age. 

The  imported  Boulogne  Portland  cement,  after  getting  a 
permanent  set,  will  sustain  a  load  of  1000  pounds  per  square 
inch.  Its  tensile  strength  is  340  pounds  per  square  inch.  It  is 
most  desirable  for  strong  masonry,  wharves,  piers,  founda- 
tions, sewers,  etc.,  and  concrete  sidewalks.  It  takes  several 
hours  to  set. 

For  Mortar  of  Great  Strength — One  part  Boulogne  cement, 
five  parts  coarse  sand. 

Selenitic  Lime  or  Cement — Is  prepared  by  mixing  and  grind- 
ing together  unslacked  high-degree  hydraulic  lime  and  calcined 
plaster  of  paris,  in  the  proportion  of  ninety  per  cent,  lime  and 
ten  per  cent,  plaster  of  paris.  When  made  into  mortar  with 
sand  it  sets  quickly  and  firmly,  and  can  be  used  for  concrete  of 
mason's  work ;  is  durable  and  very  firm  and  strong.  The  only 
selenitic  process  cement  used  in  this  country  is  the  Howe's  Cave 
cement,  New  York. 

For  certain  purposes  the  natural  light  cements,  and  those 
manufactured  in  the  United  States,  possess  sufficient  strength 
for  the  purposes  to  which  they  are  applied:  For  massive  con- 
crete foundations  and  walls,  for  the  backing  of  thick  walls  faced 
with  ashlar,  and  for  giving  hydraulic  energy  to  mortar  for  stone 
and  brick  masonry,  there  are  several  high  grades  of  Portland,  New 
York  and  Pennsylvania,  equal  to  those  imported  from  Europe. 

Cement  Mortar  for  Brick-laying. — One  part  cement,  two 
parts  sand.  For  Stone-work,  ordinary — One  part  cement,  three 
parts  sand. 

Mortar  of  Cement.— One  barrel  of  cement,  say  300  pounds, 
two  barrels  of  sand,  one-half  barrel  of  water,  will  make  say  eight 


AND    FOUNDATION   WALLS.  I2Q 

cubic  feet  of  mortar,  and  will  lay  500  bricks,  or  one  cubic  yard 
of  rubble  stone-work.  Three  or  four  more  parts  of  sand  may  be 
added,  according  to  quality  of  work. 

Cement  Mortar  for  Stone  Masonry—/,  e.,  Cut  or  Squared  Ma- 
son Work. — One  cask  of  cement,  say  300  pounds,  ninety  per 
cent,  fine;  one-half  cask  lime,  Thomaston;  fifteen  cubic  feet  of 
sand. 

The  mixing  of  lime  with  cement  makes  the  cement  set  slower, 
and  is  also  cheaper. 

Cement  Mortar  for  Brick  Masonry. — One  cask  of  cement,  one- 
half  cask  of  lime,  four  cubic  feet  paste,  and  ten  cubic  feet  of 
sand. 

Where  cements  are  used  on  masonry  of  railroad  work,  the 
proportion  of  mortar  is  one-third  of  cement  to  two-thirds  of 
sand,  and  sometimes  lime  is  added. 

Ordinary  Concrete.—One  part  cement,  one  part  lime,  two 
parts  sand,  and  four  parts  granite  spalls  or  shingle. 

Brickdnst  Cement  Concrete. — One  measure  or  part  of  new 
lime,  one  and  one-quarter  measures  of  part  brick  or  tile  dust, 
one  and  one-quarter  measures  of  parts  of  sand,  five  measures  or 
parts  of  broken  stone,  and  water. 

Lime  and  Cement  Concrete. — One-half  bushel  cement,  three- 
eighths  bushel  lime,  two  bushels  sand,  four  bushels  broken  stone, 
and  three-eighths  bushel  water. 

Lime  should  always  be  slacked  a  day  or  two  before  mixing 
the  concrete. 

TABULAR  STATEMENT  OF  TESTS  MADE  ON  HYDRAULIC 

AND  OTHER  CEMENTS  AT  THE  CENTENNIAL 

EXHIBITION,  PHILADELPHIA. 

All  these  cements  were  tested  by  mixing  them  dry,  in  every 
case  with  equal  quantity  of  clean  sand,  tempering  it  to  the  con- 
sistency of  stiff  mason's  mortar.  Then  they  were  moulded  into 


130 


POWELL'S  FOUNDATIONS 


small  bricks,  equal  to  two  and  one-quarter  square  inches  of  sur- 
face,  allowed  one  day  to  set  in  the  air,  and  placed  in  water  for 
six  days.  After  a  number  of  trials  on  each,  the  result  was  divided 
by  two  and  one-quarter  to  get  the  load  on  each  square  inch. 


CEMENTS. 

Crushing 
strength   per 
square  inch. 

Tensile 
strength  pei 
square    inch. 

Stettin,  German,  Portland  Cement  

1,436 
1,300 
1,150 
1,073 
968 
931 
926 
907 
882 
826 
764 
693 
606 
580 

292 
276 
276 
234 
230 
200 
184 
201 
184 
180 
126 
122 

206 
212 
200 
184 
168 
158 
192 
163 
141 
132 
108 
134 
112 
154 

38 
47 
43 
47 
44 
42 
29 
42 
42 
27 
24 
25 

Wouldhan's        "           "                       fr'si  

Portland  Wampum,  New  Castle,  Penn.,  U.  S  

ROMAN  AND.OTHEK  CEMENTS. 

Cumberland  Hydraulic  Cement  Co.,  Maryi'd,  U.  S. 

Anchor  Cement,  Allentown,  Penn.,  U.  S  

There  would  naturally  occur  many  reasons  for  the  above  tests 
being  variable,  owing  to  the  selection  of  cement  for  the  test, 
and  exposure  to  the  heat  of  the  sun,  etc.  Most  of  the  above 
data  was  obtained  from  nine  to  twelve  tests  on  each  kind  of  cem- 
ent. Thirty-three  per  cent,  of  the  test  would  give  a  fair  work- 
ing load  for  foreign  cements,  and  forty  per  cent,  for  the  United 
States,  as  every  year  great  improvement  is  being  made  in  the 
manufactures  of  all  grades  of  cement  in  this  country ;  and  the 
tests  are  open  to  such  criticism,  owing  to  competition  and  use 
here,  that  they  may  be  relied  upon. 

When  Portland  cements  are  made  into  blocks  without  sand 
and  filled  in  moulds,  and  turned  out  after  twenty-four  hours, 
they  may  then  be  immersed  in  water,  and  at  the  expiration  of 


AND    FOUNDATION    WALLS.  ijj 

eight  days  they  will  give  a  tensile  strain,  slowly  applied,  of  250 
Ibs.  to  the  square  inch. 

On  Cements.— Mr.  F.  Collingwood,  Civil  Engineer,  has  made 
a  number  of  exhaustive  experiments  at  the  East  River  Bridge, 
N.  Y.,  on  cements.  He  states,  that  in  mixing  water  with 
cement,  the  quantity  of  water  used  was  limited  to  produce  the 
best  result.  This  varied  with  every  lot  of  cement,  even  from 
the  same  maker.  That  which  in  one  case  would  make  a  clean, 
hard  briquette,  would  in  another  not  give  any  coherence  when 
rammed.  The  percentage  of  water  is  given  in  the  annexed 
table,  this  was  sufficient  to  make  the  mass  slightly  moist ;  after 
this  it  was  rammed  in  the  moulds.  About  one-half  more  water 
would,  in  each  case,  give  a  mortar  of  the  right  consistency  for 
use.  The  sieve  used  had  2500  meshes  per  square  inch.  There 
were  forty  individual  tests  :  ten  tests  for  twenty-four  hours,  ten 
for  seven  days,  ten  for  fourteen  days,  and  ten  at  twenty-one 
days'  setting ;  the  briquettes  being  made  at  the  same  time  and 
from  the  same  barrel.  The  briquettes  were  2x11-2  in  the  break- 
ing section,  with  ends  enlarged  to  fit  the  clamps  in  the  testing 
machine.  In  compression  a  portion  of  the  same  specimen  was 
crushed,  the  size  was  2x2x1  I.-2.  The  twenty-four  hour  tests 
are  no  criterion  as  to  the  ultimate  strength  of  cements.  Further 
tests  were  made  to  compare  brick  for  tensile  and  compressive 
strains,  but  it  is  stated  they  were  not  very  satisfactory ;  yet 
here  is  the  result. 

Haverstraw  brick  were  used,  not  the  hardest 

Of  whole  bricks,  10  tests,  set  on  end,  compression  averaged  2,065  Ibs.  per  square  Inch. 

10  half  bricks  on  side,  "  "  4,612    «•      "        " 

10      "        "  flat,  "  "  3,371    "       "         " 

These  tests  seem  to  compare  favorably  with  a  table  of  tests 
also  made  in  New  York,  see  page  81.  Twelve  bricks  were 
carefully  cut  to  fit  the  cement-testing  machine.  The  tensile 
strength  averaged  ninety  pounds  per  square  inch.  All  of  these 
experiments  when  they  are  properly  done,  give  the  preference  to 
well  and  carefully  laid  full  size,  hard-burned  brick  over  cement 


132 


POWELL'S  FOUNDATIONS 


COLLINGSWOOD  ON  CEMENTS. 
CEMENT   TESTS;    EAST   KIVEE  BRIDGE— NEW   YORK. 


Air  Tension. 

Air 
Compression. 

Water 
Tension. 

Water 
Compression. 

Fineness. 
Water,  pr.  ct. 

Baylor's  Portland, 
"       Excelsior, 
Coolidge  Portland, 
Newark    Lime    & 
Cement  Co., 
Lawrenceville, 
Ramsey, 
N.  Y.  &  Rosendale, 
F.  O.  Norton, 
Round  Top, 

Time. 
Days. 

Time. 
Days. 

Time. 
Days. 
T~T~UH 

80  174  191  250 
19   94142161 

77  192  197  227 
22   76   71    78 
65   65    79108 
29   39   37   25 
48   53    58   82 
58    75104121 
74    72    S3    94 

Time. 
Days. 

96  18to2» 
98  25 

90  25  to  30 
9825 
90  25  to  30 

89  28 
81  23 
97  25 
87  22 

17     14  21 

17       14    21 

17      14     21 

115  205  216  218 
111  110  156  187 

67  80  97   97 
91  119  137  '.'OS 

57   99109153 
65  148  151  180 
79  123  102  159 

1168180317001747 
1405  1770 

1151042   7901448 
770  80018082326 

180   532   656   902 
397    900   0931330 
592  1902  1875  1887 
606    755  1094  24i)5 

1146  1698  1621  2025 
210    95012551275 

840  2365  2448  3377 
400    882    6401014 
555   475   9571767 
135   455   358   286 
305   374    3321275 
71H  1487  127--)  15C2 
6-20    480    889  2115 

Roman  Cement. — Slacked  lime  one  bushel,  green  copperas 
three  and  one-half  pounds,  fine  gravel  sand  one-half  bushel. 
Dissolve  the  copperas  in  hot  water,  and  mix  all  together  to 
the  proper  consistency  for  use ;  use  the  day  it  is  mixed  and 
keep  stirring  it  with  a  stick  while  in  use. 

Yicat's  Hydraulic  Cement — Is  prepared  by  stirring  into  water 
a  mixture  of  four  parts  chalk  and  one  part  clay  ;  mix  with  a  ver- 
tical wheel  in  a  circular  trough,  letting  it  run  out  in  a  large  re- 
ceiver. A  deposit  soon  takes  place  which  is  formed  into  small 
bricks,  which  after  being  dried  in  the  sun  are  moderately  cal- 
cined. It  enlarges  about  two-thirds  when  mixed  with  water. 

Hydraulic  Cement.— Powdered  clay  three  pounds,  oxide  of 
iron  one  pound ;  and  boiled  oil  to  form  a  stiff  paste. 

Stone  Cement.— River  sand  twenty  parts,  litharge  two  parts, 
quick-lime  one  part ;  mixed  with  linseed-oil. 

Glue.— Powdered  chalk  added  to  common  glue  strengthens  it. 
A  glue  which  will  resist  the  action  of  water  is  made  by  boiling 
one  Ib.  of  glue  in  two  quarts  of  skimmed  milk. 

Cement  Mortar — If  one  measure  (slightly  compacted  by  shak- 
ing.) of  ground  cement  be  mixed  with  about  one-third  of  a 
measure  of  water,  it  forms  about  two-thirds  of  a  measure  of 
paste  fit  for  mortar.  Perfectly  fresh  cements  require  a  little 


AND    FOUNDATION    WALLS.  133 

more  water  than  old,  and  cements  differ  among  themselves  as 
to  the  proper  quantity  of  water.  If  sand  is  to  be  added,  more 
water  will  of  course  be  needed,  but  this  should  be  added  in  very 
small  quantities  as  the  mixing  or  tempering  goes  on,  inasmuch 
as  a  much  less  quantity  is  required  than  would  at  first  sight  be 
supposed.  So  also  on  the  addition  of  lime,  as  before  remarked, 
the  pure  cement  is  stronger  without  any  addition  whatever  of 
either  lime  or  sand  ;  still  it  will  be  quite  strong  enough  for  most  or- 
dinary purposes,  especially  when  not  exposed  to  water,  even  with 
a  considerable  addition  of  both.  But  if  it  is  to  be  exposed  to  ab- 
solute contact  with  water,  lime  should  be  added  but  sparingly,  if 
at  all  in  the  outer  joints.  When  the  sand  is  in  the  proportion 
of  one  or  more  measures  to  one  of  cement,  the  bulk  of  mixed 
mortar  will  be  about  equal  to,  or  a  trifle  less  than  that  of  the 
dry  sand  alone. 

The  cement  mortar  of  the  Croton  Aqueduct  of  New  York, 
was  as  follows  :  for  the  brick  inside  lining  of  the  aqueduct,  one 
measure  cement  powder,  two  measures  sand;  for  the  stone 
backing,  one  measure  cement  powder,  three  measures  sand. 

When  mortar  is  to  be  exposed  to  dampness  only,  we  may  use 
cement,  one  ;  quick-lime,  one  ;  sand,  four  to  six  parts.  The  lime 
should  be  thoroughly  slacked  before  it  is  added. 

Quantity  Required. — A  barrel  of  cement,  300  pounds  and  2 
barrels  of  sand  (6  bushels  or  7  1-2  cubic  feet),  mixed  with  about 
1-2  a  barrel  of  water,  will  make  about  eight  cubic  feet  of  mor- 
tar sufficient  for : 

192  square  feet  of  mortar  joints  1-2  inch  thick. 
288        "         "  "  "      3-8     " 

384       "         "  "  "       i-4     " 

768        "         "  "  "       1-8     " 

Or,  to  lay  I  cubic  yard,  or  522  bricks  of  8  1-4  by  4  by  2  inches, 
with  joints  3-8  inch  thick  ;  or  a  cubic  yard  of  roughly  scabbled 
rubble  stone  work.  The  quantity  of  sand  may  be  increased 
however,  to  3  or  4  measures  for  ordinary  work. 

Concrete  is  merely  a  coarse  mortar  of  lime,  sand  and  gravel 
or  broken  stone.  Engineers  generally  apply  to  it  the  French 
name  of  Beton  when  cement  is  used,  instead  of  common  lime. 
When  first  mixed  and  deposited,  the  concrete  occupies  consider- 


124  POWELL'S  FOUNDATIONS 

.ably  less  bulk  than  that  of  its  dry  materials  ;  but  in  setting  it 
swells  permanently  about  1-30  part  of  its  thickness.  This  last 
property  has  been  supposed  to  render  it  peculiarly  valuable  for 
underpinning;  but  as  it  also  renders  the  concrete  porous  and 
friable,  the  argument  has  but  little  force. 

A  common  proportion  among  English  engineers  is  I  measure 
of  ground  quick-lime,  I  1-2  of  water,  and  6  to  8  of  gravel.  Brok- 
en stone  is  often  added,  and  still  better,  fragments  of  brick. 
Every  11-4  cubic  yards  of  gravel  makes  about  I  cubic  yard  of 
concrete.  In  using  concrete,  the  entire  width  of  the  foundation 
trench  should  be  filled  with  it  and  it  should  be  well  rammed  in 
layers  about  a  foot  thick,  as  it  is  deposited. 

Gen.  Totten,  in  his  work  on  mortars,  gives  the  following 
formula  for  cement  concrete,  which  he  used  with  perfect  success 
where  "springs  of  water  flowed  over  the  work  continually,  and 
were  allowed  to  cover  each  days  work.  The  next  morning  the 
concrete  was  always  found  hard  and  perfectly  set."  It  was  ram- 
med as  it  was  deposited.  When  not  to  be  rammed  he  would 
somewhat  increase  the  proportions  of  all  the  ingredients  except 
the  stone  fragments,  to  insure  the  filling  of  all  the  voids  between 
these  last. 

1  1-3  measures  of  good  Rosendale  cement  powder, 

2  measures  of  sand, 

4          "         "  granite  fragments  of  nearly  uniform  size  and 

about  5  ounces  weights, 
1-2  measure  of  water  nearly. 

These  gave  a  little  more  than  4  measures  of  concrete,  or 
about  the  same  as  the  granite  fragment  alone  ;  and  each  barrel 
of  cement  (300  Ibs.,  or  3  packed  bushels)  made  16  7-10  cub.  ft., 
or  nearly  .62  cub.  yards  of  concrete :  or  a  cub.  yd.  of  the  con- 
crete required  1.61  barrels  of  cement.     The  General  adds  that 
if  one-half  of  the  cement  had  been  omitted,  and  its  place  sup- 
plied by  quick-lime  in  about  the  following  proportion,  the  work 
would  still  have  been  very  hydraulic,  and  very  strong : 
.6  measures  of  cement, 
.4       "  "    quick-lime, 

2.0       "  "    sand, 

4-O       "  "    granite  fragments, 

•  5       "  "    water  nearly. 


AND   FOUNDATION   WALLS.  135 

The  4  measures  of  quick-lime  to  be  thoroughly  slacked,  be- 
fore being  mixed.  He  also  gives  the  following,  as  forming  a 
very  hard  concrete,  when  rammed  : 

i    measure   good    Rosedale   cement  powder, 
i  1-4      "  sand, 

3  "  clean  gravel, 

33  per  cent,  water. 

Another  rammed  concrete  "became  very  hard,  but  was  rather 
too  incohesive  while  fresh,  to  make  the  best  factitious  stone." 

1  meas.  good  Rosendale,  Norton's  and  Baylors'  cement  powder, 

2  measures  sand, 

3  "        clean  gravel, 
3-8       "        (about,)  water. 

The  concrete  used  on  the  Croton  Aqueduct,  New  York,  con- 
sists of 

i  meas.  good  New  York  cement  powder, 

3    "       clean  sand, 

3    "       hard  stone,  broken  to  pass  through  a  ring 

I  1-2  ins.  diam. 
A  very  good  concrete  is  composed  of 

i    measure   cement  powder, 

1  1-2     "        clean  sand, 

2  3-4     "        gravel, 
0.35  (about,)  water. 

These  5  1-2  measures  give  about  4  1-2  of  concrete. 

The  following  brick-dust  hydraulic  concrete  has  been  used 
with  success  in  some  important  French  works : 

I  measure  quick-lime  slightly  hydraulic, 
i  1-4     "     brick,  or  tile  dust, 
i  1-4     "      sand, 

5  "      (nearly),  broken  stone. 

These  8  1-2  measures  gave  about  5  1-2  of  concrete.  This 
concrete  was  impervious  to  water. 

Coignet's  beton.  The  artificial  stone  which  bears  this  engi- 
neer's name  has  for  several  years  been  used  in  France  with  per- 
fect success  not  only  for  dwellings,  depots,  large  city  sewers, 


{^6  POWELL'S  FOUNDATIONS 

etc.,  but  for  piers,  and  arches.  It  is  composed  of  5  measures 
of  sand,  7  measures  of  finely  ground  quick-lime,  from  1-4  to  1-2 
measures  of  ground  Portland  cement,  (or  6  parts  of  sand  may 
be  used.)  These  are  first  well  mixed  together  dry  ;  and  then 
placed  in  a  grinding  mill,  at  the  same  time  sprinkling  them  with 
a  very  small  quantity  of  water  so  as  to  moisten  them  without 
wetting  them.  They  are  then  thoroughly  incorporated  by 
grinding  until  they  form  a  tough  or  stiff  mass.  It  is  then  put 
in  moulds  and  compacted  with  a  i6-lb.  hammer  :  slow  settling 
cement  is  the  best ;  the  blocks  or  slabs  will  set  in  from  a  few 
hours  to  a  day  or  more,  this  depends  on  the  size  of  blocks  that 
are  made.  It  may  be  used  for  foundation  walls,  piers  and  arches 
— and  where  extra  strong  construction  is  required  and  it  is  not 
convenient,  or  is  too  expensive  to  use  stone ;  where  there  is 
considerable  of  this  to  be  done  it  will  not  cost  more  than  one- 
half  as  much  as  stone. 

TEST  TO  SHOW  THE  PURITY  OF  PORTLAND  CEMENT. 

In  order  to  discover  whether  cement  has  been  adulterated, 
with  blast-furnace  slag : — Take  80  grains  (Troy  weight)  of  the 
suspected  cement  and  put  into  a  glass  vessel  or  graduate  con- 
taining 775  grains  of  dilute  muriatic  acid  (containing  one  part 
of  pure  acid  to  four  parts  of  water) ;  the  mixture  should  be  well 
stirred  with  a  glass  rod. 

Pure  cement  is  not  rendered  turbid  or  thick  by  this  treat- 
ment.  If  on  the  contrary  the  liquid  turns  milky,  from  the  pres- 
ence of  sulphur  in  suspension,  while  at  the  same  time  the  yel- 
lowish tinge  disappears  and  a  strong  smell  of  sulphuretted  hy- 
drogen becomes  perceptible  this  is  an  indication  that  cinders 
have  been  added.  The  presence  of  ground  limestone,  or  chalk 
may  be  detected  in  a  similar  manner  by  the  occurrence  of  ebul- 
lition at  the  time  when  the  liquid  acid  is  added  to  the  cement. 
The  quantity  of  adulterated  materials,  may  be  approximately 
found  by  the  amount  of  ebullition  or  air  bubbles. 

Pure  Portland  cement  does  not  effervesce  upon  the  addition 
of  acid  ;  because  it  does  not  contain  the  carbonate  of  lime,  but 
is  composed  chiefly  of  Lime,  Silica,  Alumnia,  Oxide  of  Iron, 
Sulphuric  Acid  and  water. 


AND   FOUNDATION   WALLS.  137 

The  proportion  of  these  ingredients  vary  in  samples  from  dif- 
ferent localities  ;  but  lime  is  always  about  60  per  cent,  of  the 
whole,  the  remainder  is  composed  of  the  above  named  ingredi- 
ents ;  sulphate  of  lime  should  not  exceed  one  per  cent.  The 
greatest  value  is  attached  in  Germany  to  the  presence  of  mag 
nesia:  English  and  French  cements  seldom  contain  one  per 
cent,  of  this  substance,  but  the  proportion  rises  to  3  per  cent 
in  some  German  cements. 

The  most  essential  points  in  the  manufacture  of  cements, 
apart  from  the  tests ;  are  uniformity  of  mixing,  and  burning, 
and  fine  grindings  ;  without  this  the  material  is  valueless. 

If  there  is  too  much  sulphate  of  magnesia  in  the  preparation 
it  will  precipitate  on  the  surface  of  walls,  and  leave  that  discol- 
oration so  objectionable  where  it  is  the  intention  to  retain  the 
color  of  the  brick. 

Street  Pavements.— In  England  about  1842  many  wooden 
pavements  were  laid  in  every  style.  The  roadways  were  pre- 
pared with  sand  surfaces,  boards  laid  flat  on  the  surface,  and 
lumber  or  timber,  cut  at  all  angles,  with  cross-pieces  set  in. 
Then  again  tarred  boards  were  set  on  edge,  and  round  chest- 
nut and  other  varieties  of  woods  set  on  edge,  and  turned  and 
squared.  Planked  roads  of  every  variety  were  made  in  certain 
localities.  Ten  years  after  most  of  these  had  worn  out,  and 
been  renewed,  or  they  had  disappeared.  But  now  the  wood  is 
prepared  with  salts  of  lime,  iron,  copper,  etc.,  and  coated  with 
asphaltum,  and  in  some  localities  in  London  they  seem  to  have 
come  into  use  again. 

Wooden  pavements,  that  were  laid  of  the  various  patents  in 
New  York  City  have  nearly  all  disappeared.  The  best  appeared 
to  be  those  coated  with  asphalt,  and  set  on  edge  on  a  wooden 
board  surface,  leaving  spaces  that  were  filled  with  gravel.  The 
heavy  traffic  and  wear  from  the  large  trucks  in  New  York  soon 
destroys  the  surface,  and  keeps  the  streets  in  an  almost  impas- 
sable condition  in  winter.  They  have  not  been  renewed  in 
New  York.  In  Elizabeth,  N.  J.,  and  many  other  parts  of  New 
Jersey,  where  wooden  pavements  have  been  laid,  they  have 
lasted  only  from  five  to  seven  years.  When  they  are  partially 


!38  POWELL'S  FOUNDATIONS 

worn  out  the  accumulation  of  water  under  them,  with  exposure 
to  air,  and  sun,  soon  rots  the  the  whole  surface. 

A  properly  laid  Macadamized  pavement  is  decidedly  superior, 
when  properly  done,  to  any  wooden  pavement.  All  round-wood 
pavements  become  uneven  after  the  expiration  of  one  or  two 
years,  and  are  as  bad  as  an  uneven  cobble-stone  roadway. 

Some  wooden  pavements  laid  in  Boston,  Mass.,  seem  to  have 
met  with  better  success  than  in  the  States  of  New  York  and 
^ew  Jersey.  There  the  wooden  blocks  were  set  on  edge  on  a 
?and  bottom  six  inches  deep.  Wooden  pavements  laid  of  pine 
3r  spruce  cost  on  an  average  $  2.25  per  square  yard. 

The  next  kind  of  pavements  that  has  been  used  extensively 
in  suburban  cities,  and  some  in  New  York  and  Boston,  are 
known  as  asphaltum  or  bituminous  concrete  pavements  and 
sidewalks ;  but  the  severity  of  the  climate  here  is  such  that  the 
frost  in  winter  breaks  and  injures  them  to  such  an  extent  that 
they  are  not  considered  a  reliable  pavement  as  far  north  as  this,, 
although  the  appearance  and  surface  for  walking  is  so  desirable. 
They  cost  from  $2.00  to  $3.00  per  square  yard. 

Flag-stone  sidewalks  4  feet  in  width  are  the  best  for  village 
walks.  They  average  from  three  to  four  inches  thick.  Of 
course  if  the  width  is  greater  it  adds  to  the  expense. 

Stone  flagging  5  feet  wide  will  average  65  cents  per  running 
foot  of  that  width. 

Sidewalks  with  stone  curbing,  and  laid  with  hard  bricks  in  the 
various  styles,  may  be  laid  successfully,  where  there  is  a  tenden- 
cy for  the  frost  to  raise  the  surface,  by  providing  a  sand  bottom 
of  twelve  inches  in  depth;  and  slushing  the  surface  with  a. 
grouting  of  cement  and  lime.  Roll  the  surface  before  it  sets, 
and  lay  the  brick  in  a  grouting  of  cement.  This  can  be  done 
very  fast  by  ordinary  labor,  and  it  has  made  most  excellent 
work.  Have  a  firm  bottom. 

Macadamized  Roadways — Are  usually  built  by  laying  down 
eighteen  inches  of  large  stone,  blended  with  fine  sand  or  gravel 
and  somewhat  smaller  stone  six  inches  in  depth.  Then  on  this 
six  inches  of  ordinary  broken  stone  and  gravel,  each  layer  when 
placed  being  subjected  to  a  heavy  roller,  water  being  freely  used. 
On  country  roads  water  is  dispensed  with. 


AND   FOUNDATION   WALLS.  139 

Artificial  Stone  Pavements  or  Sidewalks. — There  are  several 
varieties  of  these  in  the  United  States,  but  they  do  not  seem  to 
stand  well  when  laid  as  far  north  as  New  York  City  or  Boston. 
They  are  mostly  made  of  Portland  cement,  and  large  sharp  sand, 
in  blocks  from  three  to  six  inches  in  thickness,  and  from  two  to 
six  feet  square.  The  proper  method  is  to  lay  them  on  a  con- 
crete foundation.  Porous  material  is  the  best  for  making  con- 
crete, as  it  allows  the  cement  to  enter  the  pores ;  all  stone  and 
gravel  should  be  wet  before  adding  the  cement.  One  of  the 
best  pavements  of  this  kind  is  the  Schillinger  artificial  stone 
pavement,  and  costs  an  average  of  20  cents  per  square  foot. 
He  also  makes  an  asphaltum  paving  block,  laid  on  .concrete. 
The  blocks  are  about  four  by  twelve  inches,  and  are  not  affected 
by  the  action  of  frost  as  ordinary  asphaltum  pavements  are. 

New  York  City,  Brooklyn,  Jersey  City  and  Newark  use  the 
following  street  pavements : 

Belgian  Pavement. — This  consists  of  stones,  5x6x6  inches, 
laid  on  a  bed  of  sand  six  inches  deep.  These  vary  in  size  to 
4x8x10,  set  on  edge.  Cost  about  $  3.50  per  square  yard.  They 
are  using  on  Vesey  street,  N.  Y.,  a  fine  paving  stone,  a  kind  of 
moderately  soft  granite,  from  the  vicinity  of  Richmond,  Virgin- 
ia. Large  quantities  of  paving  stone  come  from  New  Jersey, 
known  as  Trap  and  Basalt  stones. 

Guidet  Pavement.— This  consists  of  granite  blocks,  averaging 
12x5x8  inches,  laid  on  six  inches  of  concrete  and  six  inches  of 
sand.  It  is  laid  on  Broadway,  New  York,  and  costs  about  $5.00 
per  square  yard. 

Sidewalks.— The  sidewalks  in  New  York  City  and  Brooklyn 
are  laid  with  blue-stone  flagging  of  various  thicknesses,  and  is 
brought  from  quarries  convenient  for  transportation  down  the 
North  River.  Granite  flags  are  sometimes  used,  averaging  ten 
inches  in  thickness,  and  sometimes  measure  8  feet  by  15  feet 
These  require  no  curbing.  The  blue-stone  costs  about  $3.00 
per  square  yard. 

In  Baltimore,  Boston  and  Philadelphia  brick  is  chiefly  used, 
cost  varying  to  suit  localities,  say  $  1.20  per  square  yard. 

Concrete  sidewalks  are  made  of  a  mixture  of  tar  and  gravel ; 


j4o  POWELL'S  FOUNDATIONS 

.and  a  concrete  of  asphaltum  cement  and  gravel  is  also  used,  but 
they  do  not  seem  satisfactory  for  much  travel,  owing  to  the  ac- 
tion of  frost  and  ice  in  winter. 

Street  pavements  in  Boston  are  usually  of  granite  blocks,  4X 
7x8  inches,  laid  in  from  8  to  12  inches  of  gravel  or  sand,  and 
cost  about  $3.25  per  square  yard. 

In  Buffalo  and  Rochester,  Medina  stone  is  used ;  the  blocks 
vary  from  2  to  4x8x8  inches,  and  are  laid  on  16  inches  of  sand, 
gravel  or  broken  stone.  They  cost  about  $  3.00  per  square  yard, 
and  are  very  satisfactory. 

Method  of  Calculating  Loads  on  Floors,  etc. — Illustrations  44 
.and  45  show  a  plan  and  elevation,  representing  piers  and  walls 
of  a  structure  adjoining  another  building,  or  independent.  Also 
show  diagrams  of  loads  supported  on  floors.  The  base  stones 
are  of  ordinary  size,  and  generally  such  sized  base  stones  are 
used  where  the  load  is  not  important.  In  buildings  that  carry  an 
•actual  load  on  each  floor  of  say  160  pounds  per  square  foot  of  floor 
surface  it  is  best,  where  the  bottom  is  firm,  to  lay  two  bases  or 
footing  stones,  the  first  stone  to  average  five  feet  square,  and 
the  second  four  feet  six  inches  square,  with  a  brick  pier  built  on 
them,  say  three  feet  four  inches  square,  bonded  with  four-inch 
flat  stone — (blue-stone) — every  two  feet,  and  capped  with  a 
granite  block,  ten  to  twelve  inches  thick. 

It  is  important  that  all  piers  to  support  inside  columns 
(whether  of  iron  or  wood)  should  have  brick  and  mason-work  done 
in  the  best  manner,  with  equal  joints,  and  allowed  to  dry  in 
toward  the  center  of  pier  before  placing  the  weight  of  several 
stories  on  it,  when  the  load  comes  direct  on  the  piers.  In  ref- 
erence to  the  load  of  goods,  materials,  etc.,  in  stores,  after 
making  a  calculation  of  ten  or  twelve  stores,  the  load  in  the 
stores  on  the  first,  second  and  third  stories  did  not  exceed  170 
pounds  per  square  foot  of  surface,  and  above  that  the  load  would 
average  from  90  to  100  pounds  per  square  foot  of  surface.  Al- 
low for  load  on  roof  for  snow,  etc.,  90  pounds  per  square  foot. 
In  warehouses,  such  as  for  hardware,  cottons,  groceries,  etc., 
the  load  averaged  260  pounds  per  square  foot  of  surface.  As  a 
guide  and  a  safe  rule,  the  Building  Department  has,  for  this  pur- 
pose, tables  of  the  load  on  floors,  which  you  will  find  on  page  82 


AND   FOUNDATION   WALLS. 


~ 


IT 


»5SQ 

! 

r. 

1 

1 

I 

. 

, 

— 

— 

\ 

1 

*— 

ILLUSTRATION  44- 


!42  POWELL'S  FOUNDATIONS 

The  average  sized  piers  used  for  store  construction  run  as  fol- 
lows :  For  four  and  five  story  buildings,  where  the  business 
done  is  ordinary,  piers  average  from  three  to  three  feet  eight 
inches  square,  with  base  stones  five  feet  to  five  feet  eight  inches 
square.  Some  double  stores  (fifty-feet  front),  lately  built  in 
New  York,  have  a  line  of  piers  in  the  center,  supporting  iron 
columns.  These  piers  are  2  ft.  x  2  ft.  8  in.  x  10  ft.  high,  with  the 
first  footing  stone,  5  ft.  6  in.  x  5  ft.  x  16  in.  thick ;  the  second 
footing  4ft.  x  4  ft.  6  in.  square,  by  12  in.  thick ;  these  buildings 
are  seven  stories  or  98  feet  high. 

The  footings  and  base  stones  to  Stewart's  store,  Tenth  street, 
New  York,  did  not  average  above  six  feet  six  inches  square. 
This  structure  is  about  130  feet  high  above  the  footings.  The 
footings  and  base  stones  to  the  Western  Union  Telegraph 
Building,  New  York,  average  eight  feet  square  and  twelve  inches 
thick,  and  some  parts  have  inverted  arches.  This  building  is 
144  feet  high  from  footing  stone  to  top  of  main  cornice,  and 
above  this  is  an  iron  roof  three  stories  in  height.  The  footings 
for  the  Morse  Building,  Nassau  street,  New  York,  are  eight 
feet  square,  and  the  piers  are  five  feet  square.  The  walls  aver- 
age three  feet  four  inches  thick  to  second  floor.  This  building 
is  160  feet  high.  The  Coal  and  Iron  Exchange,  Courtlandt 
street,  is  constructed  on  piers  and  inverted  arches  on  the  fronts 
facing  the  streets. 

In  illustration  44,  showing  piers  and  walls,  the  method  of 
calculating  the  load  on  floors  by  the  square  foot  is  shown  by  the 
diagram.  The  space  from  the  wall  to  the  center  of  the  pier  is 
figured  22  feet,  and  from  one  pier  to  the  other,  1 5  feet.  To  ascer- 
tain the  load  sustained  on  the  columns,  and  on  each  pier,  multi- 
ply 15  by  22=330  square  feet.  This  multiplied  by  a  load  of  250 
pounds  per  square  foot  will  give  a  load  on  each  floor,  supported 
by  column  on  pier,  of  330  square  feet,  multiplied  by  250  pounds 
per  square  foot,  equals  82,500  pounds.  This  load  is  independent 
of  the  weight  of  materials  required  in  the  construction. 
Of  course  every  floor  has  to  be  calculated,  which  sometimes 
shows  an  immense  load  resting  on  the  piers.  Where  wooden 
girders  are  used,  the  piers  are  placed  from  ten  to  twelve  feet 
from  centers.  When  iron  girders  are  used,  the  piers  are  usually 
from  twelve  to  sixteen,  eighteen  or  twenty  feet  on  centers. 


AND   FOUNDATION   WALLS. 


143 


82500  LBS.  LOAD 


LBS.  LOAD 


ELEVATION 


ILLUSTRATION  45. 


144 


POWELL'S  FOUNDATIONS 


The  load  on  base  stone  should  not  exceed  five  and  one-half  tons 
per  square  foot  of  bearing  surface  on  base  stones  of  five  feet 
square,  which  gives  twenty-five  square  feet.  All  base  stones  in 
and  about  New  York  City  for  good  construction  have  from  six 
to  eight  inches  of  concrete  for  a  bed. 

It  is  not  unusual  with  a  good  foundation  to  load  base  stone 
to  piers  with  from  seven  to  eight  tons  per  square  foot  of  surface. 

Thickness  of  Walls  for  any  Number  of  feet  in  Height. 

— See  following  table. 

When  it  is  the  intention  to  use  stone-walls  instead  of  brick, 
(broken-range  work,  or  quarry-faced  range,)  add  from  four  to 
eight  inches  to  the  thickness  given  for  brick-walls  in  these 
tables. 

TABLE   OF   THE   THICKNESS  OF   BBICK-WALLS 

FOR   STORES,  WAREHOUSES  AND  BUILDINGS  THAT 

REQUIRE  EXTRA  STRENGTH. 


Total  height 
of  wall  in  ft. 
to  be  erected. 

Total  length 
of  wall  in  ft. 
to  be  built. 

Thickness  in 
feet  and 
inches. 

Ft.,  in. 

100 

ISO 

3 

IOO 

70 

2      8 

90 

150 

3 

90 

70 

2      6 

80 

ISO 

2    6 

80 

70 

2      6 

70 

150 

2    4 

70 

60 

.  2     4 

60 

175 

2    4 

60 

50 

2 

50 

1  60 

2 

So 

45 

2O 

40 

150 

20 

60 

2    4 

55 

2 

45 

2O 

35 

20 

30 

16 

One-twelfth  or  one-fourteenth  of  the  height  of  each  story  is 
an  average  for  the  thickness  of  a  wall. 


AND    FOUNDATION   WALLS. 


TABLE  OF  TLE  THICKNESS  REQUIRED  FOR  BRICK-WALLS  FOR  STORES, 
RESIDENCES,  ETC. 


Total  height 
of  wall  in  ft. 
to  be  erected. 

Total  length 
of  wall  in  ft. 
to  be  built. 

B'sement 
itory  in 
inches. 

First    1 
story  in 
inches.  \ 

8  Second 
toru   in 
inches. 

~TMrd~ 

tz? 

Fourth 

t3£ 

Fifth 
ttory  in 
inches. 

V 

iMfcK 

100 

100   to    125 

32 

24 

24 

20 

16 

16 

13 

100 

80 

28 

24 

20 

20 

16 

12 

100 

45 

20 

20 

16 

16 

16 

18 

** 

90 

100   to    125 

32 

24 

20 

20 

16 

16 

90 

70 

24 

20 

20 

20 

16 

16 

90 

45 

20 

20 

20 

16 

16 

16 

80 

100   to    125 

28 

24 

20 

16 

16 

13 

80 

60 

20 

20 

16 

16 

16 

13 

80 

45 

20 

20 

16 

16 

12 

12 

70 

100 

24 

20 

16 

16 

16 

is 

70 

55 

20 

16 

16 

12 

13 

8 

70 

40 

20 

16 

16 

12 

13 

8 

60 

100 

20 

20 

16 

16 

12 

8 

60 

50 

20 

16 

n 

12 

8 

60 

30 

20 

16 

12 

12 

8 

50 

100 

20 

16 

16 

12 

.. 

In  using  the  above  tables  for  thickness  of  walls  in  Baltimore, 
Philadelphia,  Washington,  etc.,  the  walls  average  more  in  pro- 
portion, owing  to  the  brick  being  larger  than  in  other  parts  of 
the  United  States.  Use  for  eight-inch  walls  8  3-4  inches  ;  for 
twelve-inch  walls,  13  inches;  for  sixteen-inch  walls,  171-2 
inches ;  for  twenty-inch  walls,  21  1-2  inches ;  for  two-feet  walls, 
26  inches,  etc. 

Footings  are  twice  the  thickness  of  basement  walls. 

All  divisions  on  party  walls  between  dwellings  should  be  at 
least  twelve  inches.  When  the  walls  are  eight  inches  the  wood 
beams  of  floors  for  each  side,  cut  through  them. 


THE  ART  OF  PREPARING  FOUNDATIONS, 

WITH  PARTICULAB  ILLUSTRATION  OF  THE 

"METHOD  OF  ISOLATED  PIERS," 

AS  FOLLOWED  IN  CHICAGO. 

BY  FREDERICK  BATJMANN,  ARCHITECT. 
Eevised  by  G.  T.  POWELL,  A.  and  C.  E. 

WITH  NINETEEN  WOODCUTS. 


The  art  of  constructing  foundations  comprises  two  distinct 
but  interdependent  parts  :  FIRST,  the  art  of  treating  the  ground  ; 
and  SECOND,  the  art  of  building  the  base. 

FIRST  PART. 

The  Art  of  Treating  the  Ground. — All  ground  from  the  nature 
of  things,  is  compressible — will  yield  under  pressure.  This  is 
owing  to  three  different  natural  causes  ;  FIRST,  general  compres- 
sibility of  mattery  which  is  so  slight  that  in  practice  it  causes  no 
concern ;  SECOND,  imperfect  packing  of  the  constituent  parts  and 
incipient  fluidity,  which  induces  to  study  and  care,  though  posi- 
tive artificial  treatment  be  not  needed ;  THIRD,  semi-fluidity, 
which  in  most  cases  calls  for  positive  artificial  treatment.  Ac- 
cordingly, I  shall  consider  the  different  building-grounds  under 
the  head  of  three  distinct  classes :  solid  grounds,  compressible 
grounds,  semi-fluid  grounds. 

Class  I.— Solid  Grounds.— This  class  comprises  rock,  gravel, 
dry  sand,  in  their  natural  beds,  and  of  sufficient  thickness  of 
strata.  The  treatment  is  very  simple,  and  in  most  cases  alike. 
Excavations  must  be  made  to  remove  loose  deposits  and  expose 


ISOLATED    PIERS.  147 

the  natural  bed.  Surfaces  must  be  made  level,  because  bases 
should  not  be  started  upon  inclined  planes.  In  this  manner  the 
most  common  engineering  routine  will  ever  attain  good  results 
as  to  foundations.  .The  ground  being,  for  all  ordinary  practical 
purposes,  next  to  incompressible,  differences  in  the  weights  of 
the  various  parts  of  the  superstructure  produce  no  manifest  de- 
fects. Neither  is  there  any  considerable  manifestation  of  piers 
or  corners  deviating  from  the  line  of  the  perpendicular,  though, 
perchance,  such  piers  or  corners  were  not  centrally  supported. 
Concrete  or  no  concrete,  inverted  arches  or  no  inverted  arches, 
random  work  or  work  rightly  considered,  the  result  is  practically 
ever  the  same ;  the  slight  deviations  from  the  true  lines,  which 
may  occur,  pass  unnoticed ;  the  builder  has  nought  to  think  on 
the  subject ;  his  common  every-day  routine  suffices  him  in  all 
his  cases,  and  he  remains  in  ignorance  as  to  the  proper  princi- 
ples by  which  the  true  art  of  preparing  foundations  is  governed. 
Their  practice  was  upon  ground  of  the  first  class,  which  prevails 
in  most  of  the  large  cities  of  the  country,  and  taught  them  noth- 
ing to  the  point ;  nor  could  they  avail  themselves  of  the  experi- 
ence of  others,  inasmuch  as,  beyond  this  present  treatise,  there 
is  (as  far  as  at  present  known)  nothing  in  print  even  pretending 
to  give  information.  The  evolution  of  the  "method  of  isolated 
piers"  is  but  the  result  of  modern  wants  as  to  the  construction 
of  mercantile  buildings. 

Class  II.  —  Compressible  Grounds.— This  class  comprises 
clay  and  watery  sand,  and  mixtures  of  the  two,  a  whole  scale  of 
grounds,  from  the  border  of  the  first  class  downward  to  semi-flu- 
idity. The  successful  erection  of  any  ordinarily  heavy  structure 
upon  such  ground  involves  the  consistent  application  of  two 
well  known  (and  often,  though  loosely  mentioned)  principles : 
FIRST,  the  areas  of  base  must  be  in  proportion  to  the  superincum- 
bent loads  ;  SECOND,  the  centers  of  these  areas  of  base  must  coincide 
with  the  axis  of  their  loads. 

These  principles  are  self-evident,  well  known,  and  often  loose- 
ly mentioned,  yet  so  seldom  observed.     It  is  indeed,  needless 
prove  that  ten  square  feet  of  bearing  surface,  cateris  panbus, 
will  bear  more  weight  than  will  two  square  feet,  or  four,  or  nm< 
It  is  superfluous  to  specially  make  clear  the  fallacy  of  placn 


I48  BAUMANN'S  FOUNDATIONS 

che  axis  of  any  load  upon  or  near  the  edge  of  a  base,  or  in  any 
measure  away  from  its  very  center.  The  natural  result  of  such 
foolish  proceedings  would  be  that,  as  the  ground  yields,  the 
base  assumes  an  inclined  position,  and  the  axis,  which  must  re- 
tain its  original  angle  with  the  base,  is  thrust  out  of  its  perpen- 
dicular line,  as  represented  by  Fig.  I.  It  is  not  then  these 


simple  principles  that  will  occupy  me  ;  it  is  rather  their  varied 
and  manifold  application  in  the  practice  of  this  difficult  "art  of 
building,"  in  which  economy,  rightly  understood,  is  a  principal 
factor,  nay,  in  fact,  the  factor,  which  really  renders  it  a  science, 
which  can  only  be  attained  by  one  who  has  acquired  a  manifold 
experience,  and  who  previously  has  had  such  a  discipline  of 
mind  as  to  enable  him  to  systematically  collect,  and  assimilate 
with  himself,  the  mental  fruits  of  his  labors. 

First  Rule. — Resolve  the  building,  upon  its  ground  plan  of  the 
lower  story,  into  isolated  parts,  and  independently  apportion  to  each 
its  proper  share  of  foundation.  The  first  part  of  this  is  of  old 
standing,  and  often  applied  in  exceptional  cases — for  instance, 
a  church  with  a  massive  tower.  But  the  mere  keeping  the  tow- 
er separated  from  the  other  parts  is  of  no  avail,  unless  the  lat- 
ter part  of  the  rule  is  observed,  by  special  intent  or  by  chance 
of  circumstances,  as  the  case  may  be.  It  is  this  matter  of  re- 
solving a  complex  building  into  isolated  parts,  a  task  requiring 
experience  and  sagacity.  Scarcely  are  there  any  two  buildings 
alike  in  this  respect,  and  the  question  ever  arises,  where  shall  I 
stop  ?  With  some  buildings  it  may  be  simple,  so  that  the  old 
every-day  routine  may  suffice. 

Second  Rule. — Estimate  the  weights  of  all  those  (really  and 
ideally)  isolated  parts,  in  order  to  apportion  to  each  its  due  share 
of  foundation.  To  this  end  it  is  required  to  know  the  bearing  capacity 


AND    ISOLATED    PIERS. 


149 


of  the  particular  ground,  and  also  whether  or  not,  and  in  what  ratio, 
the  load  may  be  increased  in  proportion  to  the  area  of  base.  If 
it  were  found,  for  instance,  that  the  medium  bearing  capacity 
(reduced  to  a  convenient  unit)  is,  say  two  tons  per  square  foot — 
meaning  that  under  such  proportionate  load  the  ground  will  be 
compressed  in  a  limited  known  ratio — and  if  it  were  further 
known  (approximately  so  at  least)  that  this  ratio  holds  good  for 
any  amount  of  load,  the  task  is  at  once  simple.  A  pier  weigh- 
ing 1 20  tons  must  receive  a  base  pressing  upon  an  area  of  60 
square  feet ;  a  pier  weighing  20  tons  must  press  upon  an  area  of 
only  10  square  feet,  and  so  on  in  this  proportion.  It  will  be  found, 
however,  that  the  proportion  varies  with  the  nature  of  the 
ground.  Ground  least  fluid  and  most  solid  (dry  clay)  will  thus 
give  too  much  support  to  the  lesser  loads  ;  ground  approaching 
semi-fluidity  will  give  them  too  little.  In  each  case,  therefore, 
where  the  properties  of  the  ground  are  not  fully  known  in  ad- 
vance, tests  must  be  instituted  for  their  ascertainment,  and  the 
apportionment  made  accordingly. 

Third  Rule. — Determine,  upon  the  ground  section,  centers  (and 
center  lines)  of  all  (isolated)  parts,  'which  in  upright  section  will  be 
the  axis  (and  axial  planes)  of  these  parts,  and  place  the  (masonry) 
bases  so  that  the  centers  of  their  areas  of  contact  will  coincide  with 
the  first  centers.  It  means  that  foundations  must  be  made  to 
support  their  loads  centrally.  The  observation  of  this  rule  is  of 
the  utmost  importance,  for  upon  it  will  depend  the  perpendic- 
ularity of  all  the  walls  and  the  corners  of  the  structure.  Let  all 
parts  have  central  foundations,  and  no  inherent  tendency  will 
exist  to  disturb  this  perpendicularity.  There  will  in  such  case 
be  no  particular  need  of  any  anchors,  except  for  temporary  use, 
while  in  the  contrary  case  the  strongest  and  best  applied  anchors 
will  not  suffice  to  preserve  the  exact  normal  position  of  the  walls 
and  corners.  Have  the  bottom  right,  and  all  else  will  come  right 
without  many  further  precautions. 

I  comprise  the  above  three  important  rules  under  the  head  c 
"Method  of   Isolated  Piers,"   which   I  advance  as  a  scientific 
method  in  opposition  to  the  old  random  method  of  continuous 
feundations. 

I  am  aware   that  Isolated  foundation-piers  are  < 


,cO  BAUMANN'S  FOUNDATIONS 

Such  isolation  of  piers  has  been,  however,  the  exception,  not  the 
rule.  Its  origin  is  from  chance  and  circumstance,  not  from 
logic.  I,  on  the  other  hand,  advance  a  principle  which  makes 
isolated  piers  the  rule  in  all  cases,  and  continuous  foundations  the 
exception,  where,  for  instance,  piers  of  uniform  -weights  are  so 
close  to  each  other  that  the  bases  will  interconnect. 

Objection  might  be  raised  to  this  new  method,  on  the  ground 
that  any  building-ground  may  not  be  everywhere  of  the  same 
uniform  density.  This  circumstance  will  but  seldom  occur, 
and  if  and  wheresoever  it  does  so,  the  greater  difficulty  should 
be  a  spur  to  greater  care  and  perseverance.  It  would  in  such 
case  be  requisite  to  make  the  most  careful  survey  of  the  ground, 
to  determine  the  degrees  of  variations  in  density,  and  map  the 
same,  in  order  to  obtain  a  correct  basis  for  estimation  and  ap- 
portionment. 

The  Building-ground  of  Chicago. — The  subsoil  throughout 
is  of  blue  clay,  covered  by  sand  and  loam,  which,  below  the 
level  of  ground-water,  become  "quicksand"  and  "blue  muck." 
(n  the  central  part  of  the  city  the  clay  is  found  at  a  depth  of 
•'bout  five  feet  from  the  original  surface,  which  now  is  about 
right  feet  below  the  established  grade  of  streets.  This  clay-bed 
is  more  or  less  permeated  by  water,  which  enters  through  a  net- 
work of  fine  gravelly  veins,  and  through  the  river  channel ;  it 
is,  therefore,  varying  in  its  bearing  capacity  in  proportion  to  its 
state  of  humidity,  the  driest  clay  of  course  being  the  hardest, 
and  therefore  the  best  for  purposes  of  foundation.  In  the 
central  part  of  the  city  the  clay-bed  has  a  distinct  surface,  cov- 
ered with  a  scattered  stratum  of  boulder-gravel,  and  is  termed 
"hardpan."  It  approaches  the  surface  to  within  five  feet. 
Throughout  the  West  Division  the  clay  is  equally  near  to  day- 
light, though  it  has  no  distinct  surface,  the  loam  gradually 
changing  into  clay. 

From  State  Street  eastward,  the  dip  of  the  clay -bed  is  so  steep 
that  already  within  one  block  it  becomes  ordinarily  impracticable 
to  reach  it.  Nor  is  this  necessary,  for  the  overlying  soil 
answers  all  purposes.  This  soil  is  here  an  intimate  mixture  of 
clay  and  fine  sand,  in  common  parlance  termed  "blue  muck"  on 
account  of  its  shifty  nature ;  but  its  quality  as  building-ground 


AND    ISOLATED    PIERS.  15  f 

is  better  than  first  appearances  would  warrant.  Toward  the 
North  and  South  the  clay  is  covered  by  a  bed  of  fine  sand, 
which  grows  in  thickness  with  the  distance  from  the  center  of 
the  city ;  it  becomes  what  is  termed  quicksand  from  the  level  of 
ground-water  downward,  which  level  is  mostly  within  a  few  feet 
from  the  surface.  A  massive  stone  clmrck  tower  erected  upon  this 
quicksand  gradually  sank,  within  about  eight  months  after  its 
completion,  some  twenty  inches,  carrying  with  it  the  surrounding 
ground  on  a  radius  of  over  forty  feet.  There  being  apparently  no 
limit  to  this  "settling"  the  tower  was  taken  down.  Its  weight 
upon  the  base  was  probably  not  over  thirty-six  pounds  per  square 
inch. 

The  convenient  bearing  capacity  of  all  this  soil  is  twenty  pounds 
to  the  square  inch.  With  this  the  bases  in  all  ordinary  cases  be- 
come not  so  widespread  as  to  necessitate  for  their  solid  con. 
struction  any  cutting  into  the  hardpan.  Such  proportionate 
load  will  compress  the  hardpan  to  the  extent  of  about  one  inch 
during  construction  of  the  building,  and  about  one-half  of  an 
inch  during  the  next  six  months  following,  after  which  time 
the  load  appears  to  be  poised  upon  the  clay ;  the  season,  as  oft- 
en the  popular  belief  is,  having  no  share  in  this  "settling."  The 
compression  will  be  greater,  as  a  matter  of  course,  upon  the  soft- 
er portions  of  the  clay,  as  well  as  upon  the  loam,  dry  or  wet ;  it 
is  least  upon  the  dry  surface-sand,  where  this  can  be  made  avail- 
able. All  that  is  necessary  is  the  strict  application  of  the 
"method  of  isolated  piers,"  so  that  all  parts  of  the  ground  will 
be  compressed  in  the  same  degree,  causing  a  perfectly  equable 
"settling."  But  in  practice  it  will  ever  be  found  advisable  to 
base  calculations  upon  the  smallest  possible  amount  of  ultimate 
compression,  and  to  be  guided  in  this  matter  (as  we  ought  to  be 
in  all  others)  by  prudent  economy ;  hence  I  term  the  bearing 
capacity  stated  a  convenient  one.  This  matter  of  dividing  a  build- 
ing into  isolated  parts,  and  estimating  the  weight  is  by  no  means 
as  simple  as  at  first  it  would  appear,  and  may  even  in  some  cases 
offer  material  difficulties.  Take,  for  instance,  a  building  six  or 
seven  stories  high,  fire-proof,  with  fire-proof  vaults  in  the  lower 
stories.  The  outer  and  some  of  the  inner  walls  are  of  full  height ; 
other  inner  walls  are  one,  two  or  five  stories  less  in  height ;  some 
of  the  vaults  extend  through  four  stories,  others  stop  in  the  base- 


152  BAUMANN'S  FOUNDATIONS 

ment ;  the  loads  become  shifted  by  the  location  of  the  openings : 
there  are  columns  bearing  floors  ;  the  internal  walls  and  columns 
do  not  become  loaded  as  the  building  progresses,  for  floors, 
ceilings  and  plastering  are  not  applied  before  the  building  is 
roofed.  Now  if  the  ultimate  "settling"  is  kept  within  the  limit 
of  one  and  a  half  inches,  as  it  ought  to  be,  the  problem  of  attain- 
ing a  sound  and  perfect  structure  is  solvable  through  an  ordinary 
amount  of  sagacity  and  carefulness  applied  upon  the  "method  of 
isolated  piers ;"  probable  differences  falling  within  the  limits  of 
one-quarter  to  one-half  of  an  inch,  and  causing  no  palpable  de- 
fects. 

Examples  and  Instances—  Being  an  Illustration  of  the  "Method 
of  Isolated  Piers. — Fig.  2  shows  upright  section  of  a  pier  of  an 
outer  wall,  and  elevation  of  an  abutting  dwarf-wall.  If,  as  the 
old  method  would  suggest,  in  order  to  furnish  "all  the  bearing 
possible,"  the  dwarf-wall  is  connected  with  the  pier  at  its  line 


of  intersection,  ef,  the  pier  will  be  thrust  outward,  and  the 
dwarf-wall  crack  as  indicated.  The  cause  may  readily  be  found. 
Construct  the  axis,  da,  of  the  pier,  and  see  whether  it  coincides 
with  the  center  of  area  occupied  by  the  base  of  the  pier.  Were 
the  dwarf-wall  not  connected  tf.  ^/and  a  b—ac;—\.  e.,  were  the 
construction  made  in  accordance  with  the  "method  of  isolated 
piers,"  there  would  be  no  thrust  against  the  pier  But  the 
usual  old  random  mode  of  "all  the  bearing  possible"  extends 
ie  area  of  base  inward  to  c' ',  and  thereby  shifts  the  axis  of  the 


AND    ISOLATED    PIERS. 


153 


pier  off  the  center  toward  the  outer  edge  of  the  supporting  base, 
b  c'y  which  causes  the  ground  to  be  pressed  into  an  inclined  sur- 
face and,  consequently,  the  pier  to  be  thrust  outward.  Were 
the  base  of  the  dwarf-wall  made  so  narrow  as  to  cause  a  settling 
of  the  dwarf-wall  equal  to  that  of  the  pier,  it  would  at  first  sight 
appear  as  though  then  the  wall  might  be  connected.  Yet  this 
is,  nevertheless,  forbidden  by  the  circumstance  that  the  base  of 
the  dwarf-wall  would  receive  all  its  load  before  the  pier  would  ; 
say,  one-fifth  part  of  it.  Besides,  it  is  extremely  difficult  to  pro- 
portion so  slight  a  load  with  sufficient  accuracy ;  and  the  laws 
of  nature  are  very  severe  ;  but  a  slight  deviation  of  the  axis,  d  a 
from  the  center  of  area  of  base  will  have  its  marked  effect. 
Two  rules  may  be  abstracted  from  this  instance. 

FIRST — Let  the  axis  of  the .  load  always  strike  a  little  way 


inward 'from  the  center  of  the  area  of  the  base,  in  order  to  make 
sure  that  it  will  not  be  toward  the  outside.  Any  inward  incli- 
nation of  the  pier  is  rendered  impossible  by  the  floor  beams, 
while  an  outward  inclination  must  be  counteracted  by  artificial 
means,  such  as  anchors,  which,  in  all  cases,  are  but  reliable  to 
a  certain  degree.  Anchoring  is  thus  reduced  to  safeguards  ; 
although  anchors  are  placed  on  every  sixth  or  eighth  beam  of 
each  tier  on  stores. 

SECOND— Never  connect  an  abutting  dwarf-wall  with  an  oittet 
pier  or  wall.     Build  it  independently,  with  a  distinct,  clean, 


154 


BAUMANX  S    FOUNDATIONS 


straight  joint.  In  some  cases  it  might  be  advisable  to  leave  four 
inches  of  clear  space,  to  be  walled  up  afterward. 

Fig.  3  shows  what,  in  a  measure,  occurs  to  an  old-fashioned 
four-story  building  erected  upon  continuous  foundations.  The 
middle  column,  having  no  load  to  sustain,  retains  its  original 
position  while  the  others  are  pressed  downward,  with  results  as 
represented. 

The  corner  piers,  if  not  prevented  from  doing  so  by  the  re- 
sistance of  buildings  at  the  right  and  left,  are  thrust  outward 


Because  their  axes  are  not  centrally  supported,  as  can  be  readily 
seen  without  further  explanation.  The  foundation,  in  fact,  re- 
solves itself  into  piers,  but  in  a  manner  contrary  to  sound  engi- 
neering, giving  to  the  lightest  pier  the  largest  support.  Before 
the  great  fire,  scores  of  similar  fronts  were  seen  in  Chicago,  nor 
has  the  lesson  been  thoroughly  understood  after  this  great 
event. 

_    Years  after  the  "method  of  isolated  piers"  had  slowly  taken 

ts  course,  some  new  comer  of  an  architect  took  it  upon  him- 

f  to  show  his  colleagues  that  he  could  overcome  the  difficulty 

by  means  of  inverted  arches.     The  result  was  a  building  on  the 


AND    ISOLATED   PIERS.  j^- 

corner  of  Washington  and  Dearborn  Streets,  as  here  represented 
by  Fig.  4.  The  extent  of  the  front  was  forty  feet ;  the  lintel 
was  one  piece  of  timber,  connecting  the  piers  and  columns  of 
the  front,  causing  all  to  incline,  parallel  with  the  corner  pier  to 
the  extent  of  nearly  three  inches  out  of  their  perpendicular 
lines.  It  is  not  difficult  to  conceive  that  good  inverted  arches 
have  a  greater  effect  upon  shifting  the  axis  of  load  off  the  cen- 
ter of  base  than  has  a  mere  continuous  foundation  (or  a  contin- 
uous bed  of  concrete) ;  likewise,  that  the  thrust  of  the  arch  it- 
self, if  any  such  occurs,  would  have  the  tendency  to  counteract 
rather  than  enhance  the  difficulty  arising  from  oblique  settling 
of  the  base. 


n     n     n 


JFIV 


The  case  grows  serious  with  Fig.  5,  which  represents  part  of 
a  front,  consisting  of  alternate  heavy  and  light  piers.  Contin- 
uous foundations,  or  beds  of  concrete,  or  inverted  arches,  would 
have  a  tendency  to  thrust  the  corner  pier  outward,  and  to  break 
the  horizontal  connections  over  the  little  piers,  as  has  been 
demonstrated  by  the  former  examples.  But  even  the  smallest 
admissible  bases  might  prove  troublesome  in  regard  to  the  little 
piers.  In  such  cases,  resort  may  be  had  to  an  entire  omission 
of  bases  for  such  little  piers,  and  to  the  introduction  of  some 
bearing  connection  from  large  to  large  pier  for  their  support,  as 
shown  in  Fig.  5.  A  case  has  occurred  very  lately  in  Chicago, 
where  the  bases  of  such  heavy  piers  were  made  too  small,  and 


IS6 


BAUMANN'S  FOUNDATIONS 


those  of  the  lighter  piers  too  large  (isolated  piers  were  here 
employed  without  method).  The  effect  was  that  the  sinking 
heavy  piers  hung  themselves,  with  part  of  their  weight,  by 
means  of  very  stiff  horizontal  connections,  on  the  little  piers, 
and  literally  crushed  them.  Had  these  crushed  piers  been 
stronger  than  the  horizontal  connections,  the  latter  would  be- 
come seriously  damaged.  As  it  was,  the  building  underwent 
jack-screw  operation  and  insertion  of  new  piers.  In  cases 
where  there  are  mere  mullions  in  the  larger  lower  windows,  as 
represented  in  Fig.  6,  if  the  mullions  are  supported  on  iron 


construction  from  large  piers  on  each  side,  piers  under  will  not 
be  required  ;  otherwise,  direct  foundations  under  these  mullions 
will  be  necessary,  and  the  piers  to  be  proportioned  to  sustain 
the  load  above. 

A  prominent  building  lately  erected  with  such  mullion  piers 
upon  direct  foundations  was  merely  saved  by  the  fact  that, 
firstly,  it  was  placed  upon  old,  well  settled  foundations,  and,  sec- 
ondly, that  the  three  upper  stories  of  the  design  were  omitted, 
leaving  the  building,  as  it  now  stands,  four  stories  high.  The 
consequence,  thus  far,  is  the  mere  fracture  of  one  of  the  power- 
ful stone  lintels  covering  the  basement  openings  (as  indicated 
by  dotted  line). 

The  case  assumes  a  different  aspect  under  Fig.  7,  yet  it  is 
readily  shown  to  belong  to  the  same  class.  In  1852, 1  construct- 
ed the  front  of  a  blacksmith's  shop  in  the  manner  shown  by 
Fig.  7,  with  this  result,  that  the  keystone  of  the  doorway  arch 
dropped  downward.  The  inverted  arch  owed  its  existence  to 
the  universal  random  idea  of  "get  all  the  bearing  you  can." 


AND    ISOLATED    PIERS. 

But  when  the  piers  e  /and  g  h  are  considered  by  themselves,  it 
is  not  difficult  to  observe  that,  through  the  very  introduction  of 
this  inverted  arch  (or  continuous  rubble  wall  or  concrete),  the 
axes  of  these  piers  become  shifted  off  the  centers  of  their  bases, 
att*l,  consequently,  thrust  outward;  hence  the  dropping  of  the 


keystone.  The  fact  is,  that  a  front  thus  constructed  compresses, 
the  ground  under  its  base  to  a  convex  plane,  while  on  the  other 
hand,  by  the  principle  demonstrated  in  the  discussion  of  Fig.  2, 
it  should  be  so  constructed  as  to  compress  the  ground  to  a  plane 
slightly  concave,  which  may  be  readily  effected  by  omitting  the 
foundation  under  the  opening. 


158 


BAUMANN'S  FOUNDATIONS 


The  reader  will  now  fully  understand  the  reason  why  the  arch- 
es  over  almost  all  large  openings  (in  churches  etc.)  have  more 
or  less  parted.  He  will  understand  from  Fig.  8  why  the  arches 
over  the  center  of  the  ill-fated  Court  House  wings  were  rent. 
The  law  acts  with  unerring  certainty,  no  matter  what  the  ex- 
tent  of  the  front,  no  matter  how  slight  the  cause.  But  to  fur- 
nish  a  most  striking  example  of  the  minuteness  with  which  this 
law  operates,  I  produce  Fig.  9,  which  is  intended  to  represent 
a  view  of  the  east  gable  of  the  (destroyed)  celebrated  Crosby 
Opera  House.  The  foundation  wall,  twelve  feet  high,  was 
built  of  rubble  stone  in  cement  mortar,  and  had  ample  time  to  set, 
since  the  brick  wall  was  not  started  thereon  until  about  two 
months  afterward.  The  base  was  five  feet  wide  upon  the  hard- 
pan,  the  brick  wall  twenty  inches  thick  for  twenty  feet  high, 


and  sixteen  inches  for  the  following  sixty  feet.  The  load  upon 
the  base  was  consequently  about  twenty-six  pounds  to  the 
square  inch.  The  whole  weight  of  wall  and  base  was  850  tons, 
less  twenty  tons  omitted  by  the  two  openings.  The  ultimate 
settling  of  the  wall  could  not  have  been  over  two  and  a  half 
inches,  yet  the  slight  reduction  of  the  load  by  only  twenty  tons, 
at  its  center,  from  the  total  load  of  850  tons,  caused  the  base  to 
assume  a  slightly  convex  plane,  so  that  both  corners  were 
somewhat  thrust  over,  as  indicated  by  the  parting  of  the  arches 
over  the  openings,  which  parting  was  so  decided  that  the  cracks 
were  plainly  seen  at  160  feet  distance,  from  the  opposite  side  of 


AND    ISOLATED    PIERS. 


159 


State  Street,*  and  caused  a  whisper  among  the  unsophisticated 
passers  by  to  the  effect  that  the  house  was  unsafe.  And  all 
this  from  so  little  a  cause !  The  most  remarkable  feature  of 
this  case,  however,  is  that  the  base,  tfiirty-ttvo  feet  thick,  as  it 
were,  from  the  hardpan  to  the  sill  of  the  lower  opening,  did  ac- 
commodate itself  readily  to  the  assumed  curvature  of  the  ground ; 
that,  in  fact,  all  this  mass  of  solid  brick  and  stone  work  acted  as 
though  it  were  possessed,  in  a  measure,  by  a  minute  degree  of 


quassi-fluidity.  This  ought  to  show  to  satisfaction,  if  not  a 
proper  consideration  of  the  case  by  itself  did,  that  compressible 
ground  cannot  be  spread  over  at  random  by  concrete,  or  any 
kind  of  masonry,  and  thereby  made  exempt  from  the  operations 
of  the  "law  of  convex  deflection."  All  such  masonry,  of  what- 
soeverkind,  will,  from  its  nature,  yield  and  accommodate  itself  to 
such  curvatures  of  the  ground  as  the  different  loads  at  different 
places  will  naturally  produce,  f 

To  give  one  of  the  most  flagrant  instances  of  what  happens 
from  non-observation  of  the  biddings  of  the  "law  of  convex  de- 
flection," I  introduce  (Fig.   10)  a  section  of  the  old  water-rese 
voir  structure  on  Adams  Street,  erected  1854.     Theconseque 

-This  gable  was  a  mere  court  wall,  receding  ninety-three  feet  from ^the 
line  of  State  Street,  upon  which,  immediately  afterward,  a  tine  building 
was  erected  by  the  owner  of  the  Opera  House. 

t  Omitting  some  of  the  base  at  the  center,  by  means  of  an  arch  as  indicated, 
.vculd  have  preserved  the  exact  perpendicular  state  of  the  corners,  so  M  to 
leave  the  arches  intact. 


i6o 


BAUMANN'S  FOUNDATIONS 


was  the  immediate  discomfiture  of  the  structure  on  the  first  day 
when  the  water  was  let  on.  Even  if  other  causes  had  not  en- 
hanced this  result,  the  "law  of  convex  deflection"  alone  would 
have  been  sufficient  for  its  production.  To  render  the  concern 
serviceable,  all  openings  were  walled  up  and  an  intermediate 
inner  wall  was  built,  as  indicated  by  dotted  lines.  Nothing 
could  have  happened  had  the  foundation  been  prepared  in  ac- 
cordance with  the  "method  of  isolated  piers." 

Cross  section  through  an  outer  wall. — Fig.   1 1.      It  will 


readily  be  perceived  that,  by  dint  of  this  continuous  bed  of  con- 
crete, the  axis  d  a  is  shifted  off  the  center  of  its  base ;  the  clay 
beneath  will  consequently  be  compressed  to  a  convex  plane,  with 
a  tendency  to  thrust  the  wall  out  of  its  perpendicular  line.  This 
tendency  need,  however,  not  become  realty,  because  of  the  very 
probable  rupture  of  the  bed  of  concrete,  as  indicated  in  Fig.  1 1, 
or  else  because  the  cross  anchoring  will  be  so  effective  as  to 
prevent  such  occurrence  to  an  extent  that  will  be  noticed  by  a 
non-expert.  Had  this  wall  an  independent  central  base,  as  dic- 
tated by  the  "method  of  isolated  piers,"  no  possible  contingency 
could  ever  arise. 

2.  Considering  the  large  inequality  of  the  weights  of  the 
piers  of  the  outside  walls,  the  heavier  piers  will  sink  down,  in 
some  measure,  proportionate  to  the  weight  of  pier  and  size  of 
base  upon  the  clay,  such  as  it  may  assume  for  itself,  while  the 
little  piers  will  almost  wholly  retain  their  original  levels.  The 
difference  may  possibly  not  be  very  considerable,  and  escape 
the  eye  of  the  non-expert,  but  occur  it  must,  by  dint  of  inexora- 
ble law. 


AND    ISOLATED   PIERS.  jfo 

3.  Taking  a  view  of  a  corner  with  adjoining  pier,  Fig.  12, 
the  case  represents  itself  similar  to  what  it  does  in  Fig.  1 1,  with 
this  difference,  however,  that  in  Fig.  n,  the  concrete  is  bare  and 


H  >r~     - 

H  j  : 

may  be  readily  ruptured,  while  here  the  concrete  is  strengthened 
by  a  mass  of  the  most  excellent  masonry,  and  may  not  break  so 
as  to  save  the  corner  from  being  thrust  outward.  Besides,  the 
anchors,  as  usually  applied,  get  no  hold  at  the  corners.  To  hold 


them  would  require  a  longitudinal  and  cross  anchoring  within 
the  thickness  of  the  walls,  from  corner  to  corner,  a  troublesome 
and  expensive  proceeding.  Under  the  "method  of  isolated 
piers,"  with  observance  of  ,the  biddings  of  the  "law  of  convex 
deflection,"  the  corners  would  take  care  of  themselves  without 
anchors. 

4.  Taking  a  section  through  one  of  the  intended  internal 
piers,  Fig.  13,  the  case  assumes  a  very  serious  aspect.  The  load 
per  column  is  said  to  be  upward  of  380  tons;  the  column  is  to- 
stand  upon  an  iron  stool,  with  bottom  plate  six  feet  square, 
bedded  on  the  bare  concrete.  To  arrive  at  any  accurate,  or  even 
approximate,  estimate  of  the  efficacy  of  this  bed  of  concrete,  un- 
der existing  circumstances,  is  simply  a  matter  of  impossibility. 
A  mechanical  estimate  to  this  effect  requires  a  knowledge  of  its 


J&2          BAUMANN'S  FOUNDATIONS 

exact  absolute  and  crushing  strength,  as  well  as  ot  the  exact  de 
gree  of  the  elasticity  and  incipient  fluidity  (yielding  property)  of 
this  concrete.  Even  if  these  properties  were  ascertained  from 
samples,  it  would  by  no  means  follow  that  the  bed,  just  at  such 
particular  place,  is  altogether  precisely  according  to  the  samples. 
Trials  have  been  made  by  loading  plates  one  foot  square  with  as 
much  as  thirty  and  more  tons  upon  each.  To  conclude  from 
this  trial  upon  the  nature  of  the  cas.e  is,  I  believe,  a  fallacy. 
Even  if  one  square  foot  would  bear,  without  damage  to  the  in- 
tegrity of  this  bed  of  concrete,  say  100  tons  during  a  week,  the 
conclusion  is  by  no  means  warranted  that  it  will  carry  for  all 


n^L. 

5= 
g/ 

/ft 

| 

i*l                   s| 

«l             I            i 

«]          1            |        si 

w                  1                 «l 

«r         i        i        =i 

[                               1                              51 

time  to  come  380  tons  upon  a  spot  six  feet  square,  with  absolute 
and  infallible  certainty.  (Actual  practical  judgment,  with  an 
allowance  of  one-quarter  of  the  load  that  produces  any  move- 
ment of  depression  on  the  earth,  will  be  safe.)  The  load,  as  the 
case  is,  must  be  trusted  on  cJtance,  instead  of  on  mathematical 
certainty,  and  is,  therefore,  in  a  technical  meaning  insufficiently 
supported,  which  involves  by  no  means  a  prediction  that  in  reali- 
ty the  support  will,  or  must,  fail.  It  simply  means  that  it  may 
fail.  Any  construction  in  building  that  is  not  secure  by  dint  of 
mathematical  certainty,  is  technically  insecure,  and  therefore 
condemnable.  How  differently  does  this  case  present  itself  un- 
der the  light  of  the  "method  of  isolated  piers,"  as  is  illustrated 
by  Fig.  14.  Here  the  hardpan  is  loaded  to  a  ratio  of  about 
twenty  pounds  to  the  square  inch.  With  a  pier  well  bedded, 
and  securely  constructed  out  of  the  most  beautiful  material  so 
readily  at  hand  in  Chicago,  it  is  mathematically  certain  that  the 
ultimate  "settling"  will  be  (about)  one  and  a  half  inches.  Be- 


AND    ISOLATED    PIERS.  163 

sides,  this  construction  would  have  the  point  of  economy  in  its 
favor. 

Concrete. — Good  concrete  is  always  made  up  with  cement- 
mortar.  This  artificial  conglomerate  rock  is  spread  upon  the 
building-ground  at  large,  or  upon  the  bottom  of  foundation 
trenches,  in  a  thickness  varying,  as  the  case  may  be,  from  one 
to  five  feet  for  the  purpose  of  an  "equalizer."  Concrete  work 
at  best  is  random  work,  that  may  and  may  not  do  good  service. 
Upon  hard  and  practically  incompressible  ground,  it  is  super- 
fluous, as  a  matter  of  course,  except  what  may  be  required  for 
the  bedding  of  footing  courses.  Upon  compressible  ground  it 
will,  under  some  circumstances,  accommodate  itself  to  the  deflec- 
tions of  the  ground  caused  by  superincumbent  loads,  and  thus 
may,  if  circumstances  concur,  be  of  very  serious  damage  to  the 
structure,  under  the  "law  of  convex  deflection,"  as  before  de- 
monstrated. I  reject  random  work  as  being  contrary  to  the 
spirit  of  the  present  age,  and  recommend  in  its  place  the 
"method  of  isolated  piers"  for  foundations. 

Concrete  is  applicable  in  foundations  as  a  base  in  place  of 
other  masonry.  Its  application  is  there  justified  in  all  cases, 
where  it  chances  to  be  the  cheapest  material.  It  is  in  this  sense 
one  of  the  means  at  the  hands  of  the  engineer  for  the  attain- 
ment of  his  ends. 

Class  III.— Semi-Fluid  Grounds. — This  class  comprises  «'//, 
marsh,  peat,  and  the  like.  When  gravel  or  rock  can  be  found 
within  practicable  distance,  piers  of  some  kind  may  be  sunk 
upon  it ;  but  ordinarily  resort  is  had  to  artificially  condensing 
the  ground  by  means  of  piling. 


SECOND  PART. 

The  Base  is  alike  a  means  of  support  as  it  is  a  means  of 
spreading  out  in  order  to  convey  the  pressure  exacted  by  the 
load  upon  such  area  of  the  ground  as  has  been  determined  under 
the  "method  of  isolated  piers."  The  base  therefore  must  be 
in  every  respect  solid;  the  pressure  to  which  it  is  subjected 


i64 


BAUMANN'S  FOUNDATIONS 


must  in  no  way  move  its  constituent  parts.  The  Chicago 
material  for  bases  is :  Dimension  stone,  hard  lime-rock,  of  most 
any  dimensions,  from  eight  to  twenty  inches  thick,  and  with 
even  beds.  There  can  be  no  better  material  in  the  whole  world 
than  this  dimension  stone.  There  is  also  rubble  stone  of  the 
same  rock,  hard,  flat  bedded,  handy  as  to  size.  Concrete,  being 
inferior  to  rubble  work,  and  besides  being  more  costly,  is  out  of 
the  question,  at  least  under  a  reasonable  view  of  employing 
means  to  an  end.  For  dimension  stone  I  have  adopted  the  rule 


6'.  t 


of  making  the  offsets  somewhat  less  than  the  thickness  of  stone, 
though  I  know  of  no  instance  of  an  evil  result  from  offsets 
being  even  more  than  equal  to  the  thickness  of  stone.  For 
rubble  I  have  adopted  four  inches  of  an  offset  to  each  foot  of 
height.  For  concrete  I  should  reduce  the  offset  to  three  inches. 
Figs.  15,  1 6,  17  represent  bases  accordingly,  all  under  the  sup- 
position that  the  weight  of  the  wall  requires  a  width  of  base  of 
six  feet  eight  inches. 

For  Dimension  stone $6.90  per  foot  lin. 

"    Rubble  stone 6.90    "      "      " 

"    Concrete 14.28    "      "      " 

making  evident  the  absurdity  of  employing  concrete  in  Chicago 
foundations. 

The  money  point  grows  more  in  favor  of  rubble  stone  as  the 
base  is  narrower,  and  more  in  favor  of  dimension  stone  as  it  is 
wider,  as  can  be  readily  estimated. 

Pier  bases  ought  in  all  cases  to  be  wholly  constructed  of 
dimension  stone. 


AND    ISOLATED    PIERS.  165 

The  bedding  of  the  base  on  the  ground  offers  but  little  diffi- 
culty. Upon  sand  and  loam,  dry  or  wet,  it  beds  itself  without 
trouble.  Clay  is  best  covered  first  with  a  thin  layer  of  gravel 
or  broken  stone,  rammed  into  the  surface,  and  grouted  with  liq- 
uid cement-mortar.  A  layer  of  concrete,  from  two  and  a  half  to 
four  inches  thick,  and  rammed  partly  into  the  surface,  answers 
the  same  purpose.  Upon  the  surface  thus  prepared  mortar  is 
spread,  and  the  stone  bedded. 

The  mortar  ought  always  to  be  good  cement-mortar,  with  sand 
of  very  coarse,  gravelly  nature  as  its  component.  For  joints  of 
two  or  more  inches  in  thickness,  between  dimension  stones 
which  happen  to  have  uneven  beds,  a  mortar,  made  of  two  parts 
of  roofing  gravel  and  one  of  fresh  cement,  has  answered  excel- 
lent purpose.  By  this  the  expense  of  dressing  the  stone  is 
saved,  and  yet  the  end  attained  with  all  the  certainty  required 
in  ordinary  cases. 


I  conclude  the  subject  with  Figs.   18  and   19,  representing 
bases  of  two  of  the  tallest  chimneys  in  Chicago. 

Fig.  18  is  the  base  of  the  chimney  erected  in  1859  f°r  ^e 
Chicago  Refining  Company,  151  feet  high,  12  feet  square  at 
foot.  The  base,  merely  two  courses  of  heavy  dimension  stone, 
as  shown,  is  bedded  upon  the  surface  gravel  near  the  mouth  of 
the  river,  there  recently  deposited  by  the  lake.  The  mortar 
employed  in  the  joint  between  the  stone  is  roofing  gravel  and 
cement.  The  area  of  base  is  256  square  feet,  the  weight  of 
chimney,  inclusive  of  base,  625  tons,  giving  a  pressure  of  thirty- 
four  pounds  to  the  square  inch.  This  foundation  proved  to  1 
very  perfect. 

Fig.  19  is  the  base  of   the  chimney  erected  in  1872  I 
McCormick  Reaper  Works,  which  is  160  feet  high,    14  feet 


i66 


BAUMANN'S  FOUNDATIONS 


Z5  ' 

square  at  the  foot,  with  round  flue  of  6'  8"  diameter.  The 
base  covers  625  square  feet:  the  weight  of  the  chimney  and 
base  is  approximately  1,100  tons  ;  the  pressure  upon  the  ground 
(dry,  hard  clay)  is  therefore,  24  1-3  pounds  to  the  square  inch. 
This  foundation  too  proved  to  be  most  perfect  in  every  respect. 
24 1-3  pounds  per  square  inch  is  a  moderate  load  for  piers. 


PROPERTY  OF 
J.  W.  DONAWE, 

IPLD,  MAM. 


PROPERTY  OF 
J.  W.  DONAHUE, 


THE  LIBRARY 
UNIVERSITY  OF  CALIFORNIA 

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